JP2002348161A - Cement dispersant, its manufacturing method and its use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cement dispersant giving a high dispersibility to cement with an addition of a small amount especially even in high water reducing rigion, its manufacturing method, and a cement composition using it. SOLUTION: The cement dispersant contains a copolymer comprising a structural unit (III) derived from a specified unsaturated polyalkylene glycol ether- based monomer (a2) and a structural unit (II) derived from a specified unsaturated monocarboxylic acid-based monomer (b) as essential components, where the unit (III) shares <=50 mol.% of the total units of the copolymer and the unit (II) contains at least a unit derived from methacrylic acid (salt). The equivalent number of carboxyl group in the copolymer as converted in an unneutralized form is <=3.30 meq/copolymer of 1 g.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cement dispersant,
The present invention relates to a manufacturing method and a use thereof.

[0002]

2. Description of the Related Art In the recent concrete industry, there is a strong demand for improvements in durability and strength of concrete buildings, and in order to achieve this, reduction of unit water volume is an important issue.

Conventionally, in order to reduce the unit water volume,
The use of various cement dispersants has been proposed. Among various cement dispersants, polycarboxylic acid-based cement dispersants are particularly advantageous in that they exhibit high water reducing performance as compared with other cement dispersants such as naphthalene-based cement dispersants. The gazette proposes a copolymer derived from polyethylene glycol monoallyl ether and a (meth) acrylic acid-based monomer in a specific ratio, but this copolymer has a performance as a cement dispersant. Was still inadequate. Also, Japanese Patent Application Laid-Open No. 57-118
No. 058, JP-A-8-283350, JP-A-9-142905, and the like include copolymers derived using polyethylene glycol monoallyl ether and a maleic acid-based monomer in a specific ratio. Cement dispersants have been proposed, but these cement dispersants have satisfactory dispersibility especially in the high water reduction region due to the problem that the copolymerizability of polyethylene glycol monoallyl ether and maleic acid monomer is low. It was not at a level that I could do. On the other hand, JP-A-10-194808 proposes a cement dispersant comprising a copolymer derived from polypropylene glycol polyethylene glycol mono (meth) allyl ethers and an unsaturated carboxylic acid monomer. However, since the proportion of polypropylene glycol chains having high hydrophobicity is high, the dispersing performance is low, and a large amount of addition is required to exhibit sufficient dispersing performance, and the dispersing performance particularly in the high water reduction rate region can be satisfied At the present time, no level was available.

Further, these conventional polycarboxylic acid cement dispersants generally have a problem that the production cost is high and the cost of concrete itself rises.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a cement dispersant which exhibits high dispersibility with a small amount of addition and exhibits excellent dispersibility especially in a high water reduction rate region, and a method for producing the same. Another object of the present invention is to provide a cement composition using the same.

[0006]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that an oxyethylene group as an oxyalkylene group contains at least a specified amount or more, and the average number of moles of the oxyalkylene group is within a specified range. A specific copolymer obtained by copolymerizing an unsaturated polyalkylene glycol ether-based monomer and an unsaturated monocarboxylic acid-based monomer containing methacrylic acid (salt) as an essential component, with a small addition amount It has been found that it exhibits high dispersing performance and is useful as a cement dispersant that is inexpensive and has excellent performance. In the copolymerization, an unsaturated polyalkylene glycol ether monomer containing a polyalkylene glycol as an impurity is used as a raw material, and a specific amount of the unsaturated polyalkylene glycol ether monomer is left unreacted. It has been found that by leaving the cement dispersant, the workability of the mortar and concrete before hardening of the obtained cement dispersant can be further improved.
The present invention has been completed based on these findings.

That is, the first cement dispersant of the present invention comprises a structural unit (I) derived from an unsaturated polyalkylene glycol ether-based monomer (a1) represented by the following general formula (1): A cement dispersant comprising, as an essential component, a copolymer comprising a structural unit (II) derived from an unsaturated monocarboxylic acid-based monomer (b) represented by (2), wherein the structural unit (II) ) Contains at least a structure derived from methacrylic acid (salt).

[0008]

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(In the formula (1), X represents an alkenyl group having 2 or 3 carbon atoms; R ¹ O represents ^one or a mixture of two or more oxyalkylene groups having 2 to 18 carbon atoms;
In addition, 90 mol% or more of all oxyalkylene groups are oxyethylene groups, and n is an average number of added moles of oxyalkylene groups, and represents a number of 30 to 1,000. )

[0010]

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(In the formula (2), R ² , R ³ and R ⁴ each independently represent hydrogen or a methyl group, and M represents hydrogen, a monovalent metal, a divalent metal, an ammonium group or an organic amine group. The second cement dispersant of the present invention comprises a structural unit (III) derived from an unsaturated polyalkylene glycol ether-based monomer (a2) represented by the following general formula (3) and the following general formula (2) The unsaturated monocarboxylic acid monomer (b) represented by
A cement dispersant comprising, as an essential component, a copolymer comprising a structural unit (II) derived from the above, wherein the structural unit (III) is 50 mol% in all the structural units of the copolymer.
Occupies the following, wherein the structural unit (II) includes at least a structure derived from methacrylic acid (salt), and the carboxyl group milliequivalent number when all the carboxyl groups of the copolymer are converted to an unneutralized type is 3.30 meq or less per 1 g of the copolymer.

[0012]

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(In the formula (3), Y represents an alkenyl group having 4 carbon atoms, R ¹ O represents ^one or a mixture of two or more oxyalkylene groups having 2 to 18 carbon atoms, and 90 mol% or more of the oxyalkylene group is an oxyethylene group, m is the average number of moles of the oxyalkylene group added, and represents a number of 1 to 1,000.)

[0014]

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(In the formula (2), R ² , R ³ and R ⁴ each independently represent hydrogen or a methyl group, and M represents hydrogen, a monovalent metal, a divalent metal, an ammonium group or an organic amine group. The method for producing the cement dispersant of the present invention comprises an unsaturated polyalkylene glycol ether monomer (a) having an alkenyl group having 2 to 4 carbon atoms and an unsaturated monocarboxylic acid monomer (b). A method for producing a cement dispersant which polymerizes a monomer component containing at least: (a) an unsaturated polyalkylene glycol ether-based monomer (a) containing a polyalkylene glycol as an impurity, and From 1 to 1% of the polymer in which the unreacted unsaturated polyalkylene glycol ether monomer (a) is formed
The method is characterized in that the polymerization reaction is stopped at the time when the amount becomes 100% by weight.

The cement composition of the present invention contains the cement dispersant of the present invention, cement and water as essential components.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

[Cement Dispersant] The first cement dispersant of the present invention comprises a structural unit (I) derived from the unsaturated polyalkylene glycol ether monomer (a1) represented by the general formula (1), A copolymer (i) containing a structural unit (II) derived from the unsaturated monocarboxylic acid monomer (b) represented by the general formula (2) is contained as an essential component. Further, the second cement dispersant of the present invention is a structural unit (III) derived from the unsaturated polyalkylene glycol ether-based monomer (a2) represented by the general formula (3).
And a copolymer (ii) comprising a structural unit (II) derived from the unsaturated monocarboxylic acid monomer (b) represented by the general formula (2) as an essential component. The copolymer (i) and the copolymer (ii) may each contain a structural unit (IV) derived from the monomer (c) described below.

In the above general formulas (1) and (3), it is important that the oxyalkylene group R ¹ O contains at least 90 mol% or more, preferably 95 mol% or more of oxyethylene groups. . Thereby, the balance between hydrophilicity and hydrophobicity can be maintained, and excellent dispersion performance can be exhibited. All oxyalkylene groups R
^{If the} content of oxyethylene groups in ¹ O is less than 90 mol%, sufficient dispersibility cannot be exhibited.

In the general formulas (1) and (3), the number of carbon atoms of the oxyalkylene group R ¹ O is 2
The range of from to 18 is suitable, but the range of from 2 to 8 is preferable, and the range of from 2 to 4 is more preferable. The repeating unit of each R ¹ O may be the same or different, and the oxyalkylene group R ¹ O is not an oxyethylene group if 90 mol% or more of all oxyalkylene groups is an oxyethylene group. May be mixed. In this case, examples of the oxyalkylene group other than the oxyethylene group include an oxypropylene group, an oxybutylene group, and an oxystyrene group. When R ¹ O is in the form of a mixture of two or more kinds, the repeating unit of each R ¹ O may be any addition form such as block addition, random addition, and alternate addition.

In the general formula (1), the alkenyl group represented by X has 2 or 3 carbon atoms, but preferably has 3 carbon atoms. preferable.

In the general formula (1), it is important that the average number of added moles n of the oxyalkylene group is 30 to 1,000. Preferably 40-300, more preferably 50-300, even more preferably 60-300,
Particularly preferably, it is 60 to 200. When the average number of added moles is less than 30, the hydrophilicity of the obtained copolymer is reduced and sufficient dispersion performance cannot be exhibited. On the other hand, when it exceeds 1,000, the copolymerization reactivity is reduced. It will be.

The unsaturated polyalkylene glycol ether-based monomer (a1) represented by the general formula (1) includes, for example, polyalkylene glycol vinyl ethers, polyalkylene glycol allyl ethers and the like, and more specifically. Examples thereof include compounds obtained by adding 30 to 1000 mol of an alkylene oxide to an unsaturated alcohol such as allyl alcohol, and one or more of these can be used.

In the general formula (3), the alkenyl group represented by Y has 4 carbon atoms, and specific examples include a methallyl group and a 3-butenyl group, with a methallyl group being particularly preferred.

In the general formula (3), it is important that the average number m of added oxyalkylene groups is from 1 to 1,000. Preferably 1 to 300, more preferably 10 to 300, still more preferably 20 to 300, particularly preferably 30 to 300, most preferably 40 to 2
00. The smaller the average number of moles added, the lower the hydrophilicity of the obtained copolymer and the lower the dispersing performance tends to be. On the other hand, if it exceeds 1,000, the copolymerization reactivity decreases.

Examples of the unsaturated polyalkylene glycol ether-based monomer (a2) represented by the general formula (3) include polyalkylene glycol methallyl ethers, and more specifically, methallyl alcohol. And the like. A compound obtained by adding 1 to 1000 mol of an alkylene oxide to an unsaturated alcohol having 4 carbon atoms, such as the above, can be used, and one or more of these can be used.

The content ratio of the structural unit (I) derived from the unsaturated polyalkylene glycol ether-based monomer (a1) in the copolymer (i) or the unsaturated polyalkylene glycol ether-based in the copolymer (ii) The content ratio of the structural unit (III) derived from the monomer (a2) is preferably 1% by weight or more, more preferably 10% by weight or more, even more preferably 20% by weight or more of all the structural units. Particularly preferably at least 30% by weight,
It is most preferably at least 45% by weight. When the content ratio of the structural unit (I) or the structural unit (III) is less than 1% by weight, the dispersing performance to cement tends to decrease.

It is important that the content of the structural unit (III) is 50 mol% or less of all the structural units. Preferably 1 to 50 mol%, more preferably 2 to
It is 50 mol%, more preferably 3 to 45 mol%, particularly preferably 4 to 45 mol%. Structural unit (II
If the content ratio of I) exceeds 50 mol%, the dispersing performance in cement will decrease.

On the other hand, the content ratio of the structural unit (I) is also preferably 50 mol% or less in all the structural units, more preferably 1 to 50 mol%, further preferably 2 to 50 mol%. Particularly preferably, it is 3 to 45 mol%, and most preferably, it is 4 to 45 mol%.

It is important that the structural unit (II) contains at least a structure derived from methacrylic acid (salt), and the unsaturated monocarboxylic acid monomer (b) represented by the general formula (2) ) Must include at least methacrylic acid (salt). By including a structure derived from methacrylic acid or a salt thereof, excellent dispersibility can be exhibited with a small amount. The proportion occupied by the structure derived from methacrylic acid (salt) is preferably at least 1% by weight in all the structural units of the copolymer (i) or the copolymer (ii).
% By weight or more, more preferably 3% by weight or more. The upper limit of the proportion occupied by the structure derived from methacrylic acid or a salt thereof coincides with the upper limit of the content of the structural unit (II) described later. In the case of 25% by weight, the proportion of the structure derived from methacrylic acid or a salt thereof is preferably from 1 to 25% by weight, more preferably from 2 to 25% by weight, and still more preferably from 3 to 25% by weight, based on all the structural units. In addition, as a salt of a methacrylic acid, a monovalent metal salt, a divalent metal salt, an ammonium salt, an organic amine salt, etc. can be mentioned, for example.

As the unsaturated monocarboxylic acid monomer (b) other than methacrylic acid or a salt thereof represented by the general formula (2), for example, acrylic acid, crotonic acid, or a monovalent metal salt thereof, Examples thereof include divalent metal salts, ammonium salts, and organic amine salts, and one or more of these can be used. Among these, acrylic acid (salt) is particularly preferable, and the form containing methacrylic acid (salt) and acrylic acid (salt) as the unsaturated monocarboxylic acid monomer (b) is a preferred embodiment of the present invention. One.

The copolymer (i) or the copolymer (i)
The content ratio of the structural unit (II) derived from the unsaturated monocarboxylic acid monomer (b) in i) is preferably 1% by weight or more of all the structural units, and more preferably 2% by weight or more. More preferably, it is 3% by weight or more, still more preferably, 4% by weight or more.
Further, the upper limit of the content ratio of the structural unit (II) may be set so that the carboxyl group milliequivalent number when all the carboxyl groups of the copolymer are converted into the non-neutralized type is in the range described later. . As described later, the copolymer (i) or the copolymer (ii) is a structural unit derived from the copolymerizable monomer (c), for example, a structural unit derived from an unsaturated dicarboxylic acid-based monomer. Since a structural unit having a carboxyl group may be contained, the number of carboxyl group milliequivalents is not limited to the case where the structural unit is derived from the structural unit (II). It is necessary to set an upper limit.

The copolymer (i) and the copolymer (i)
i) is a monomer (a1) or (a) in addition to the structural unit (I), the structural unit (II) or the structural unit (III).
It may contain a structural unit (IV) derived from the monomer (c) copolymerizable with 2) and / or the monomer (b). Examples of the monomer (c) include unsaturated dicarboxylic acids such as maleic acid, maleic anhydride, fumaric acid, itaconic acid, and citraconic acid, and monovalent metal salts, divalent metal salts, ammonium salts, and organic salts thereof. Amine salts; half esters and diesters of the unsaturated dicarboxylic acids and alcohols having 1 to 30 carbon atoms; half amides and diamides of the unsaturated dicarboxylic acids and amines having 1 to 30 carbon atoms;
Alkyl (poly) obtained by adding 1 to 500 mol of an alkylene oxide having 2 to 18 carbon atoms to the alcohol or amine.
Half-esters and diesters of alkylene glycol and the above-mentioned unsaturated dicarboxylic acids; half-esters and diesters of the above-mentioned unsaturated dicarboxylic acids and glycols having 2 to 18 carbon atoms or polyalkylene glycols having an addition mole number of 2 to 500 of these glycols And unsaturated monocarboxylic acids such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, glycidyl (meth) acrylate, methyl crotonate, ethyl crotonate, and propyl crotonate; Esters with alcohols of 1 to 3 carbon atoms
Esters of alkoxy (poly) alkylene glycol obtained by adding 1 to 500 moles of alkylene oxide having 2 to 18 carbon atoms to alcohol 0 and unsaturated monocarboxylic acids such as (meth) acrylic acid; (poly) ethylene glycol mono 1 to 500 mole addition products of alkylene oxides having 2 to 18 carbon atoms to unsaturated monocarboxylic acids such as (meth) acrylic acid, such as methacrylate, (poly) propylene glycol monomethacrylate, (poly) butylene glycol monomethacrylate, etc. ; Maleamic acid and carbon number 2
To 18-glycols or half-amides thereof with polyalkylene glycols having an addition mole number of 2 to 500; triethylene glycol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, polypropylene glycol di (meth) ) Acrylates, (poly) alkylene glycol di (meth) acrylates such as (poly) ethylene glycol (poly) propylene glycol di (meth) acrylate; hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, tri Bifunctional (meth) acrylates such as methylolpropane di (meth) acrylate; (poly) alkylene glycol dimaleates such as triethylene glycol dimaleate and polyethylene glycol dimaleate Vinyl sulfonate, (meth) allyl sulfonate, 2- (meth) acryloxyethyl sulfonate, 3- (meth) acryloxypropyl sulfonate, 3- (meth) acryloxy-2-hydroxypropyl sulfonate, 3- (meth) acryloxy-2 -Hydroxypropylsulfophenyl ether, 3- (meth) acryloxy-2-hydroxypropyloxysulfobenzoate, 4- (meth) acryloxybutylsulfonate, (meth) acrylamidomethylsulfonic acid,
Unsaturated sulfonic acids such as (meth) acrylamidoethylsulfonic acid, 2-methylpropanesulfonic acid (meth) acrylamide and styrenesulfonic acid, and monovalent metal salts, divalent metal salts, ammonium salts and organic amine salts thereof; methyl Amides of unsaturated monocarboxylic acids such as (meth) acrylamide and amines having 1 to 30 carbon atoms;
Styrene, α-methylstyrene, vinyltoluene, p-
Vinyl aromatics such as methylstyrene; alkanediol mono (such as 1,4-butanediol mono (meth) acrylate, 1,5-pentanediol mono (meth) acrylate, 1,6-hexanediol mono (meth) acrylate) (Meth) acrylates; butadiene, isoprene, 2-methyl-1,3-butadiene, 2-chloro-
Dienes such as 1,3-butadiene; (meth) acrylamide, (meth) acrylalkylamide, N-methylol (meth) acrylamide, N, N-dimethyl (meth)
Unsaturated amides such as acrylamide; unsaturated cyanates such as (meth) acrylonitrile and α-chloroacrylonitrile; unsaturated esters such as vinyl acetate and vinyl propionate; aminoethyl (meth) acrylate and (meth) acrylic acid Methylaminoethyl, dimethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, dibutylaminoethyl (meth) acrylate,
Unsaturated amines such as vinylpyridine; divinyl aromatics such as divinylbenzene; cyanurates such as triallyl cyanurate; allyls such as (meth) allyl alcohol and glycidyl (meth) allyl ether; dimethylaminoethyl (meth) Unsaturated amino compounds such as acrylates; vinyl ethers or allyl ethers such as methoxypolyethylene glycol monovinyl ether, polyethylene glycol monovinyl ether, methoxypolyethylene glycol mono (meth) allyl ether, polyethylene glycol mono (meth) allyl ether; polydimethylsiloxane Propylaminomaleamic acid,
Polydimethylsiloxane aminopropylene aminomaleamic acid, polydimethylsiloxane-bis- (propylaminomaleamic acid), polydimethylsiloxane-bis- (dipropyleneaminomaleamic acid), polydimethylsiloxane- (1-propyl-3-) Acrylate), polydimethylsiloxane- (1-propyl-3)
-Methacrylate), polydimethylsiloxane-bis-
Siloxane derivatives such as (1-propyl-3-acrylate) and polydimethylsiloxane-bis- (1-propyl-3-methacrylate); and one or more of these can be used. . In particular, as the monomer (c) having a carboxyl group other than the unsaturated monocarboxylic acid monomer (b), an unsaturated dicarboxylic acid monomer such as maleic acid is suitable.

The copolymer (i) or the copolymer (i)
The content ratio of the structural unit (IV) derived from the copolymerizable monomer (c) in i) is not particularly limited as long as the effect of the present invention is not impaired. Or less, more preferably 60% by weight or less, further preferably 50% by weight or less, particularly preferably 40% by weight or less, and most preferably 30% by weight or less.
It should be:

The copolymer (i) or the copolymer (i)
The ratio of each structural unit constituting i) is, for example, structural unit (I) or structural unit (III) / structural unit (II) /
It is preferable that the structural unit (IV) is 1 to 99/1 to 30/0 to 70 (% by weight), and the structural unit (I) or the structural unit (III) / the structural unit (II) / the structural unit (I
V) = 10 to 99/1 to 30/0 to 60 (% by weight) is more preferable, and the structural unit (I) or the structural unit (III) / the structural unit (II) / the structural unit (IV) = 2
It is more preferably 0 to 98/2 to 30/0 to 50 (% by weight), and the structural unit (I) or the structural unit (II)
I) / Structural unit (II) / Structural unit (IV) = 30-9
It is particularly preferably 7/3 to 30/0 to 40 (% by weight), and the structural unit (I) or the structural unit (III)
/ Structural unit (II) / Structural unit (IV) = 45-96 /
Most preferably, it is 4 to 25/0 to 30 (% by weight) (provided that the structural unit (I) or the structural unit (III)
And the total of the structural unit (II) and the structural unit (IV) is 100% by weight. ).

The copolymer (i) and the copolymer (i)
i) is a method of polymerizing a monomer component containing the unsaturated polyalkylene glycol ether-based monomer (a1) or (a2) and the unsaturated monocarboxylic acid-based monomer (b) by a conventionally known polymerization method. Preferably, it can be obtained by copolymerization by a polymerization method in the production method of the present invention described below. Further, for example, instead of the monomer (a1) or (a2), a monomer before adding an alkylene oxide,
For example, using an unsaturated alcohol such as allyl alcohol,
This is copolymerized with the monomer (b) in the presence of a polymerization initiator (if necessary, another monomer (c) copolymerizable with these monomers is further copolymerized. ) May be obtained by adding an alkylene oxide.

The copolymer (ii) has a carboxyl group milliequivalent number of 3.30 per gram of the copolymer when all the carboxyl groups of the copolymer are converted to an unneutralized type.
It is important that it is less than meq. Preferably 0.1
0 to 3.30 meq / g, more preferably 0.15 to
3.00 meq / g, more preferably 0.20-2.
50 meq / g, particularly preferably 0.30 to 2.5
The range of 0 meq / g is good. When the number of carboxyl group milliequivalents exceeds 3.3 meq / g, the fluidity of the cement composition over time decreases, and the dispersing performance decreases over time. On the other hand, if the number of milliequivalents of the carboxyl group is too small, the dispersibility of the copolymer is significantly reduced, and it becomes difficult to obtain sufficient fluidity as a cement composition.

On the other hand, the copolymer (i) also has a carboxyl group milliequivalent number of 3.30 meq or less per gram of the copolymer, when all the carboxyl groups of the copolymer are converted into an unneutralized type. Preferably, it is more preferably 0.10 to 3.30 meq / g, still more preferably 0.15 to 3.00 meq / g, particularly preferably 0.20 to 2.50 meq / g, and most preferably 0.1 to 3.00 meq / g.
The range of 30 to 2.50 meq / g is good.

The carboxyl group milliequivalent number when all the carboxyl groups in the copolymer (i) and the copolymer (ii) are converted to the non-neutralized form can be calculated as follows. . For example, methacrylic acid is used as monomer (b), and monomer (a) / monomer (b) =
When copolymerized at a composition ratio of 90/10 (% by weight), since the molecular weight of methacrylic acid is 86, the number of carboxyl group milliequivalents per gram of the copolymer is (0.1 / 86) ×
1000 = 1.16 (meq / g) (calculation example 1). Further, for example, using sodium methacrylate as the monomer (b), the monomer (a) / monomer (b) = 90
When copolymerized at a composition ratio of / 10 (% by weight), the molecular weight of sodium methacrylate is 108 and the molecular weight of methacrylic acid is 86. .1 / 108) / (0.
9 + 0.1 × 86/108) × 1000 = 0.95 (m
eq / g) (calculation example 2). In addition, when methacrylic acid is used at the time of polymerization and the carboxyl group derived from methacrylic acid is neutralized with sodium hydroxide after polymerization, the same calculation as in Calculation Example 2 can be performed. Further, for example, using sodium methacrylate and sodium acrylate as the monomer (b), monomer (a) / sodium methacrylate / sodium acrylate = 90/5/5 (% by weight)
When copolymerized at a composition ratio of the following, the molecular weight of methacrylic acid is 8
6. Since the molecular weight of sodium methacrylate is 108, the molecular weight of acrylic acid is 72 and the molecular weight of sodium acrylate is 94, the number of carboxyl group milliequivalents per 1 g of the copolymer is (0.05 / 108 + 0.05 / 94)
/(0.9+0.05×86/108+0.05×72
/94)×1000=1.02 (meq / g) (calculation example 3).

The copolymer (i) and the copolymer (i)
The weight average molecular weight of i) is suitably in the range of 10,000 to 300,000 in terms of polyethylene glycol by gel permeation chromatography (hereinafter referred to as "GPC"), but is in the range of 10,000 to 100,000. Is preferable, the range of 10,000 to 80,000 is more preferable, and the range of 10,000 to 70,000 is still more preferable. With such a weight average molecular weight, higher dispersing performance can be exhibited as a cement dispersant.

The cement dispersant of the present invention contains the copolymer (i) and / or the copolymer (ii) as essential components. The content of these copolymers in the cement dispersant of the present invention is not particularly limited, but is preferably 20% by weight or more, and more preferably 40% by weight or more, of the solid content in the dispersant, that is, the nonvolatile content. More preferred.

The cement dispersant of the present invention preferably contains a polyalkylene glycol in an amount of 1 to 50% by weight based on the copolymer, in addition to the copolymers (i) and (ii).
More preferably 2 to 50% by weight, still more preferably 2 to 50% by weight
The content is preferably 40% by weight, particularly preferably 3 to 30% by weight. By containing a polyalkylene glycol, it becomes a dispersant that can further improve the workability of mortar and concrete. If the content of the polyalkylene glycol is less than 1% by weight, the effect of improving the workability of the mortar or concrete becomes insufficient. In addition, such a cement dispersant can be easily obtained by the production method of the present invention described later.

The polyalkylene glycol includes:
An oxyalkylene group having 2 to 18 carbon atoms is suitable, preferably an oxyalkylene group having 2 to 8 carbon atoms, and more preferably 2 to 4 carbon atoms. Further, since the polyalkylene glycol needs to be water-soluble, it has a high hydrophilicity and has 2 carbon atoms.
It is preferable that at least the oxyalkylene group, that is, the oxyethylene group is essential, and it is more preferable that the oxyalkylene group contain 90 mol% or more of the oxyethylene group. Further, the repeating units of the oxyalkylene group may be the same or different, and when the oxyalkylene group is in the form of a mixture of two or more, block-like addition, random addition, alternate addition, etc. Any of the additional modes may be used. The terminal group of the polyalkylene glycol is a hydrogen atom, an alkyl group having 1 to 30 carbon atoms or (alkyl).
A phenyl group is suitable, but a hydrogen atom is preferred. Also, as the average molecular weight of the polyalkylene glycol,
The range of 500 to 200,000 is preferred,
The range of 0-100,000 is more preferable, and 2,000
The range of -50,000 is more preferred.

Specific examples of the polyalkylene glycol include polyethylene glycol, polypropylene glycol, polyethylene polypropylene glycol, and polyethylene polybutylene glycol.
Since the polyalkylene glycol needs to be water-soluble, polyethylene glycol or polyethylene polypropylene glycol containing an oxyethylene group having high hydrophilicity as an essential component is preferable, and polyethylene glycol is most preferable.

The cement dispersant of the present invention comprises, in addition to the copolymers (i) and (ii), the unsaturated polyalkylene glycol ether-based monomer (a1) or (a2) per copolymer. Preferably, it is contained in an amount of from 100 to 100% by weight. More preferably 2 to 100% by weight, further preferably 3 to 90% by weight, particularly preferably 5 to 80% by weight
It is good to contain. By containing the unsaturated polyalkylene glycol ether-based monomer (a1) or (a2), it becomes a dispersant capable of further improving the workability of mortar or concrete. When the content of the unsaturated polyalkylene glycol ether-based monomer (a1) or (a2) is less than 1% by weight, the effect of improving the workability of mortar or concrete becomes insufficient, and on the other hand, exceeds 100% by weight. Is not preferred because the dispersibility in cement decreases. In addition, such a cement dispersant can be easily obtained by the production method of the present invention described later.

The most preferred form of the cement dispersant of the present invention is one containing both the polyalkylene glycol and the unsaturated polyalkylene glycol ether monomer (a1) or (a2) in the above-mentioned ratio.
By containing both of these components, it becomes a dispersant which is extremely excellent in workability of mortar and concrete. In addition, such a cement dispersant can be easily obtained by the production method of the present invention described later.

The cement dispersant of the present invention can be used for various hydraulic materials, that is, hydraulic materials other than cement such as cement and gypsum. And as a specific example of a hydraulic composition containing a hydraulic material, water and the cement dispersant of the present invention, and further containing a fine aggregate (sand or the like) or a coarse aggregate (crushed stone or the like) as necessary. , Cement paste, mortar, concrete, plaster and the like. Among the hydraulic compositions exemplified above, a cement composition using cement as a hydraulic material is the most common, as in the cement composition of the present invention described below.

[Method for Producing Cement Dispersant] The method for producing the cement dispersant of the present invention comprises the steps of: preparing an unsaturated polyalkylene glycol ether monomer (a) having an alkenyl group having 2 to 4 carbon atoms; A monomer component containing at least the acid monomer (b) is polymerized.

The unsaturated polyalkylene glycol ether monomer (a), which is an essential monomer component, is not particularly limited as long as it has an alkenyl group having 2 to 4 carbon atoms. It is preferable to use an unsaturated polyalkylene glycol ether monomer (a1) or an unsaturated polyalkylene glycol ether monomer (a2) represented by the formula (1) or the general formula (3). Further, an unsaturated monocarboxylic acid monomer (b), which is an essential monomer component,
Is not particularly limited, but the above-mentioned general formula (2)
It is preferable to use an unsaturated monocarboxylic acid-based monomer (b) represented by the following formula:
Alternatively, acrylic acid (salt) is preferred from the viewpoint of copolymerization reactivity. In addition, as the monomer (a) and the monomer (b), only one kind may be used, or two or more kinds may be used in combination.

The monomer components include, in addition to the monomers (a) and (b), monomers (a) and / or
Alternatively, it may contain a monomer (c) copolymerizable with the monomer (b). Examples of the monomer (c) include, for example, those described above, and an unsaturated dicarboxylic acid-based monomer such as maleic acid is particularly preferable. In addition, as the monomer (c), only one type may be used, or two or more types may be used in combination.

The ratio of each monomer in the monomer component is not particularly limited, but preferably, the unsaturated monocarboxylic acid monomer (b) is 50% by weight or less based on the whole monomer component. , More preferably 40% by weight or less, further preferably 35% by weight or less, particularly preferably 30% by weight or less,
Most preferably, it is not more than 25% by weight. If the proportion of the monomer (b) exceeds 50% by weight in the whole monomer component, the dispersion performance over time (slan broth) becomes remarkable, and sufficient dispersion performance tends not to be exhibited.
In a more preferred embodiment, (meth) acrylic acid (salt) is used as the monomer (b) in one of the monomer components.
The content is preferably at least 2% by weight, more preferably at least 2% by weight, further preferably at least 3% by weight, particularly preferably at least 4% by weight.

The ratio of each monomer in the monomer component is, for example, monomer (a) / monomer (b) / monomer (c) = 1-99 / 1-30 / 0 The range of 70 (% by weight) is appropriate, and the range of monomer (a) / monomer (b) / monomer (c) = 10 to 99/1 to 30/0 to 60 (% by weight). Is more preferable, and the range of monomer (a) / monomer (b) / monomer (c) = 20 to 98/2 to 30/0 to 50 (% by weight) is still more preferable. a) / monomer (b) / monomer (c) = 30 to 97/3 to 30/0 to 4
The range of 0 (% by weight) is particularly preferred, and the monomer (a)
/ Monomer (b) / monomer (c) = 45 to 96/4 to 25
/ 0 to 30 (% by weight) is most preferable (provided that the total of the monomers (a), (b) and (c) is 100% by weight).

In the production method of the present invention, it is important to use, as a monomer component, an unsaturated polyalkylene glycol ether-based monomer (a) containing a polyalkylene glycol as an impurity. The unsaturated polyalkylene glycol ether monomer (a) used in the present invention is obtained by adding an alkylene oxide to unsaturated alcohols such as allyl alcohol, methallyl alcohol and 3-buten-1-ol. However, in the addition reaction, when a compound having active hydrogen such as saturated aliphatic alcohols (methanol, ethanol, etc.) other than the unsaturated alcohols or water is present in the reaction system, Polyalkylene glycol may be by-produced in addition to the desired unsaturated polyalkylene glycol ether-based monomer. In the present invention, the product obtained by the addition reaction can be used as a raw material without removing the by-product polyalkylene glycol, and at the same time, the obtained cement dispersant is a copolymer and a polyalkylene glycol. And the workability of the mortar or concrete before hardening can be further improved.

The content of the polyalkylene glycol contained as an impurity is suitably from 0.5 to 50% by weight, preferably from 1 to 40% by weight, and more preferably from 2 to 40% by weight, based on the amount of the unsaturated polyalkylene glycol ether-based monomer. -30% by weight is more preferable, and 3-20% by weight is further preferable. When the proportion of the polyalkylene glycol exceeds 50% by weight, the monomer concentration at the time of the polymerization reaction tends to decrease and the conversion tends to decrease, which is not preferable.

In the production method of the present invention, the unreacted unsaturated polyalkylene glycol ether monomer (a)
It is important to stop the polymerization reaction at the time when the amount of the polymer becomes 1 to 100% by weight based on the produced polymer. This allows
The obtained product contains an unsaturated polyalkylene glycol ether-based monomer (a) in addition to the copolymer, and can exhibit excellent dispersion performance. The time at which the polymerization reaction is stopped is preferably at the time when the unsaturated (poly) alkylene glycol ether-based monomer (a) remains in the polymer at 2 to 80% by weight, more preferably at 3 to 70% by weight. %, More preferably 5%
It is preferable to set the time when 〜60% by weight remains. When the polymerization reaction is stopped when the amount of the unreacted unsaturated polyalkylene glycol ether-based monomer (a) becomes less than 1% by weight based on the produced polymer, the obtained cement dispersant becomes a mortar or concrete worker. On the other hand, if the polymerization reaction is stopped at a time point exceeding 100% by weight, the dispersibility in cement will be reduced.

The polymerization of the monomer component can be carried out by a known method such as solution polymerization or bulk polymerization. The solution polymerization can be carried out batchwise or continuously, and the solvent used in this case is water; alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol; benzene, toluene, xylene, cyclohexane, n-hexane and the like. Aromatic or aliphatic hydrocarbons; ester compounds such as ethyl acetate; ketone compounds such as acetone and methyl ethyl ketone; cyclic ether compounds such as tetrahydrofuran and dioxane; and the like. Water and carbon number 1 from solubility
It is preferable to use at least one selected from the group consisting of lower alcohols (1) to (4), and among them, it is more preferable to use water as a solvent in that the solvent removing step can be omitted.

In polymerizing the monomer component, a usual radical polymerization initiator can be used as a polymerization initiator.

Examples of the radical polymerization initiator for aqueous solution polymerization include peroxides such as ammonium persulfate, sodium persulfate, potassium persulfate and the like; hydrogen peroxide; As 2, 2 '
-Azoamidine compounds such as azobis-2-methylpropionamidine hydrochloride, 2,2'-azobis-2- (2-
Cyclic azoamidine compounds such as imidazolin-2-yl) propane hydrochloride; 2-carbamoylazoisobutyronitrile; and the like can be used.

As a radical polymerization initiator for performing solution polymerization or bulk polymerization using a lower alcohol, aromatic or aliphatic hydrocarbon, ester compound, ketone compound or the like as a solvent, for example, benzoyl peroxide is used as a peroxide. Peroxide, lauroyl peroxide, sodium peroxide, t-butyl hydroperoxide, cumene hydroperoxide, etc., and azobisisobutyronitrile, etc. can be used as the azo initiator. When a water-lower alcohol mixed solvent is used, it can be appropriately selected from the above various radical polymerization initiators.

Further, in a preferred embodiment of the present invention, it is preferable to initiate polymerization with a redox polymerization initiator using the above-mentioned peroxide and a reducing agent in combination.

The reducing agent is not particularly limited as long as it is a general reducing agent. For example, iron (II), tin (II), and titanium (III) as represented by Mohr salt , Chromium (II), V (II), Cu (I
Salts of metals in a low valence state such as I); monoethanolamine, diethanolamine, triethanolamine, hydroxylamine, hydroxylamine hydrochloride;
Amine compounds and salts thereof such as hydrazine; sodium dithionite, sodium formaldehyde sulfoxylate, addition such as sodium hydroxy methane sulfinate _{dihydrate, -SH, -SO 2 H, -NHNH} 2, -
Organic compounds containing a group such as COCH (OH)-and salts thereof; alkali metal sulfites such as sodium sulfite, sodium bisulfite, and metabisulfite; hypophosphorous acid;
Lower oxides such as sodium hypophosphite, sodium hydrosulfite, sodium hyponitrite and salts thereof; invert sugars such as D-fructose and D-glucose; thiourea compounds such as thiourea and thiourea dioxide; L-ascorbic acid (salt ), L-ascorbic acid ester, erythorbic acid (salt), erythorbic acid ester; and the like.

Specific examples of the combination of the peroxide and the reducing agent include, for example, a combination of benzoyl peroxide and an amine, cumene hydroperoxide and iron (I
Combinations with metal compounds such as I) and Cu (II). Among them, a combination of a water-soluble peroxide and a reducing agent is particularly preferable. And a combination of sodium persulfate and sodium bisulfite is particularly preferred.
A particularly preferred combination is a combination of hydrogen peroxide and L-ascorbic acid.

The amount of the peroxide to be used is preferably 0.01 to 30 mol%, more preferably 0.1 to 20 mol%, and most preferably the total amount of the monomer components. The content is preferably 0.5 to 10 mol%. When the amount is less than 0.01 mol%, the amount of unreacted monomer increases, while
If it exceeds 30 mol%, a copolymer having a large amount of oligomers is obtained, which is not preferable.

The amount of the reducing agent used is preferably from 0.1 to 500 mol%, more preferably from 1 to 200 mol%, most preferably from 10 to 500 mol%, based on the peroxide.
The content is preferably set to １００100 mol%. When the amount is less than 0.1 mol%, active radicals are not sufficiently generated, and unreacted monomers increase. On the other hand, when the amount exceeds 500 mol%, the remaining reducing agent which does not react with hydrogen peroxide increases. This is not preferred.

Further, at the time of polymerization, it is preferable that at least one of the peroxide and the reducing agent is always present in the reaction system. More specifically, the peroxide and the reducing agent do not have to be simultaneously added at once, and may be added over a long period of time, for example, they may be continuously added by dropping or divided. When the peroxide and the reducing agent are simultaneously charged at the same time, the peroxide and the reducing agent react rapidly, so that immediately after the injection, a large amount of heat of reaction makes it difficult to control the reaction, and after that, rapidly. Since the radical concentration decreases, a large amount of unreacted monomer remains. Furthermore, since the radical concentration with respect to the monomer is extremely different between the initial stage and the latter half of the reaction, the molecular weight distribution becomes extremely large, and the performance as a cement dispersant is deteriorated. The time from the introduction of one to the start of the introduction of the other is preferably within 5 hours, particularly preferably within 3 hours.

In the polymerization, in order to obtain high reactivity of the monomer, the half-life of the radical polymerization initiator is 0.5 to 500.
Hours, preferably 1 to 300 hours, more preferably 3 hours
It is preferable to carry out the polymerization reaction at a temperature of up to 150 hours. For example, when a persulfate is used as the initiator, the polymerization reaction temperature is suitably in the range of 40 to 90 ° C, but is preferably in the range of 42 to 85 ° C.
Is more preferable, and the range of 45 to 80 ° C. is more preferable. When hydrogen peroxide and L-ascorbic acid (salt) are used in combination as an initiator, the polymerization reaction temperature is 30 to
A range of 90 ° C is suitable, but a range of 35 to 85 ° C is preferable, and a range of 40 to 80 ° C is more preferable. Also,
The bulk polymerization is preferably performed within a temperature range of 50 to 200 ° C.

The reaction time during the polymerization is not particularly limited, but is, for example, suitably in the range of 0.5 to 10 hours, preferably 0.5 to 8 hours, and more preferably 1 to 6 hours. good. If the polymerization time is too long or too short, the polymerization rate and productivity are undesirably reduced.

The amount of all the monomer components used in the polymerization is preferably 50% by weight or more based on all the raw materials including other raw materials. More preferably in the range of 50-99% by weight, even more preferably in the range of 55-99% by weight, particularly preferably in the range of 55-95% by weight, most preferably 60-99% by weight.
The content is preferably in the range of 90% by weight. If the use amount of all the monomer components is less than 50% by weight, the polymerization rate and the productivity are lowered, which is not preferable. In particular, unsaturated (poly) alkylene glycol ethers such as methacrylic acid preferably used as the unsaturated monocarboxylic acid monomer (b) and maleic acid preferably used as the monomer (c) When a monomer having relatively low copolymerization reactivity with the monomer (a1) or (a2) is used, if the amount of all monomers used is too low, the polymerization rate is greatly reduced. Is not preferred.

As a method of charging each monomer into the reaction vessel at the time of polymerizing the monomer component, the polymerization of the unsaturated monocarboxylic acid-based monomer (b) into the reaction vessel in the polymerization step is performed. The reaction vessel of the unsaturated (poly) alkylene glycol ether-based monomer (a) with respect to the charging ratio (% by weight of the charged monomer (b) relative to the total amount of the monomer (b)) It is preferred that there be a point in time at which the cumulative charging ratio (weight% of the charged monomer (a) with respect to the total charging amount of the monomer (a)) is large. By adopting such a charging method, the monomer (a) and the monomer (b) can be obtained although the polymerizability of the monomer (a) is lower than that of the monomer (b). ) Can be efficiently copolymerized. Specifically, the following method is exemplified.

The whole amount of the monomer (a) is put into the reaction vessel at a time before the polymerization is started, and after the start of the introduction of the polymerization initiator into the reaction vessel, the whole amount of the monomer (b) is divided or continuously divided into the reaction vessel. How to throw.

The whole amount of the monomer (a) and a part of the monomer (b) are charged into the reaction vessel before the polymerization is started, and the monomer (b) is charged after the polymerization initiator is started to be charged into the reaction vessel. Method of dividing or continuously charging the rest of the mixture into a reaction vessel.

A part of the monomer (a) is charged into the reaction vessel before the start of the polymerization, and the remainder of the monomer (a) and the monomer (b) are added after the start of the introduction of the polymerization initiator into the reaction vessel. Is a method in which the whole amount is divided or continuously charged into a reaction vessel.

A part of the monomer (a) and a part of the monomer (b) are charged into the reaction vessel before the polymerization starts, and the monomer (a) is added after the polymerization initiator is started to be charged into the reaction vessel. ) And the remainder of monomer (b) are divided or continuously charged into a reaction vessel, and the monomer (b) reaction vessel A method to delay the end time of loading into the system.

A part of the monomer (a) and a part of the monomer (b) are charged into the reaction vessel before the polymerization is started, and the monomer (a) is charged after the polymerization initiator is charged into the reaction vessel. ) And the remainder of monomer (b) are divided or continuously charged into a reaction vessel, and the cumulative charging ratio of monomer (b) to the reaction vessel (based on the total amount of monomer (b) charged) , The weight of the charged monomer (b)), the cumulative charging ratio of the monomer (a) to the reaction vessel (the charged monomer relative to the total amount of the monomer (a) charged). A method in which there is a time point where (% by weight of (a)) is large.

After the initiation of the introduction of the polymerization initiator into the reaction vessel, the total amount of the monomer (a) and the total amount of the monomer (b) are divided or continuously charged into the reaction vessel, and the monomer (b) Of the monomer (a) to the reaction vessel with respect to the cumulative charging ratio (weight% of the charged monomer (b) with respect to the total amount of the monomer (b)) to the reaction vessel A method in which there is a point in time when the ratio (weight% of the charged monomer (a) with respect to the total amount of the charged monomer (a)) is large.

The method of charging the monomer (c) into the reaction vessel is not particularly limited. A method in which the whole amount is initially charged into the reaction vessel at once, a method in which the whole amount is divided or continuously charged in the reaction vessel, and some methods. May be charged into the reaction vessel at an early stage, and the remainder may be divided or continuously charged into the reaction vessel.

At the time of polymerization, it is preferable to use a chain transfer agent in order to adjust the molecular weight of the obtained copolymer. In particular, when acrylic acid is used as the unsaturated monocarboxylic acid monomer (b), it is effective to use a chain transfer agent, and the unsaturated (poly) alkylene glycol ether monomer (a) When a (poly) alkylene glycol methallyl ether-based monomer is used and acrylic acid is used as the unsaturated monocarboxylic acid-based monomer (b), it is particularly effective to use a chain transfer agent.

The chain transfer agent may be any compound capable of adjusting the molecular weight. Specific examples thereof include mercaptoethanol, thioglycerol, thioglycolic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, thiomalic acid, and the like. Thiol chain transfer agents such as octyl thioglycolate, octyl 3-mercaptopropionate, 2-mercaptoethanesulfonic acid, n-dodecylmercaptan, octylmercaptan, butylthioglycolate; carbon tetrachloride, methylene chloride, bromoform, bromotrichloroethane Secondary alcohols such as isopropanol; phosphorous acid, hypophosphorous acid, and salts thereof (sodium hypophosphite, potassium hypophosphite, etc.), sulfurous acid, hydrogen sulfite, dithionous acid, Metabisulfite and its salts Sodium oxide, potassium sulfite, sodium bisulfite, potassium bisulfite, sodium dithionite, potassium dithionite, sodium metabisulfite, potassium metabisulfite, etc.) and its salts; Can be.

Further, a monomer having a high chain transfer property can be used as a chain transfer agent. Specifically, α, β-unsaturated dicarboxylic acid compounds such as maleic acid, fumaric acid, citraconic acid, and the like; Derivatives, salts thereof and the like can be used. More specifically, examples of the derivative include, for example, half esters with an alcohol having 1 to 30 carbon atoms; half amides with an amine having 1 to 30 carbon atoms; half amides with an amino alcohol having 1 to 30 carbon atoms. Or half-esters; alkylene oxide having 2 to 18 carbon atoms in the alcohol in an average of 1 to 300
Half esters with the compound (x) added by mole addition; half amides with the compound obtained by aminating a hydroxyl group at one end of the compound (x); glycol having 2 to 18 carbon atoms or the average number of moles of these glycols added Half esters with 2-300 polyalkylene glycols; glycols having 2-18 carbon atoms or half amides of polyalkylene glycols having an average addition mole number of these glycols of 2-300 with maleamic acid; Examples of are: monovalent metal salts, divalent metal salts, ammonium salts, organic amine salts); allyl compounds such as allyl alcohol and allyl sulfonic acid (salt); methallyl alcohol and methallyl sulfonic acid (salt) And the like.

It is also possible to use two or more of the above exemplified chain transfer agents in combination.

The chain transfer agent is preferably supplied so as to be always present in the reaction system during polymerization. In particular, when a thiol-based chain transfer agent or a lower oxide and a salt thereof are used as the chain transfer agent, the chain transfer agent is not charged at once, but is continuously charged by dropping or the like, or dividedly charged. It is effective to add over a long period of time. In the early and late stages of the reaction, the concentration of the chain transfer agent with respect to the monomer is extremely different, and when the chain transfer agent is insufficient in the latter half of the reaction, the molecular weight of the copolymer becomes extremely large, and as a cement dispersant, Performance will be degraded.

When the chain transfer agent is supplied to the reaction system, it is preferable to supply the chain transfer agent in a line different from the acidic raw material such as the unsaturated monocarboxylic acid monomer (b) and the peroxide. In particular, when a thiol-based chain transfer agent or a lower oxide or a salt thereof is used as the chain transfer agent, it is effective to supply the chain transfer agent through a line different from the acidic raw material. For example, when the thiol-based chain transfer agent is supplied through the same line as the unsaturated monocarboxylic acid-based monomer (b), the chain transfer agent serves as a polymerization initiator in the unsaturated monocarboxylic acid-based monomer (b).
, A partial polymerization occurs, a homopolymer is easily generated, and the performance as a cement dispersant is deteriorated. Also, when the lower oxide or its salt is supplied in the same line as the peroxide, the lower oxide or its salt reacts with the peroxide and loses its activity before the peroxide acts as a polymerization initiator. Would be.

The copolymer obtained by the production method of the present invention can be used as it is as a main component of a cement dispersant, but from the viewpoint of handleability, the pH should be adjusted to 5 or more. preferable. The polymerization may be carried out at a pH of 5 or more. In this case, however, the polymerization rate decreases, and at the same time, the copolymerizability deteriorates and the performance as a cement dispersant decreases. It is preferable to adjust the pH to 5 or more after the polymerization. The pH can be adjusted using, for example, an alkaline substance such as an inorganic salt such as a hydroxide or carbonate of a monovalent metal or a divalent metal; ammonia; an organic amine;

The copolymer obtained by the production method of the present invention may be used as it is as a main component of a cement dispersant in the form of an aqueous solution,
Powdered by neutralizing with a hydroxide of a divalent metal such as magnesium to form a polyvalent metal salt and then drying, or drying by carrying on an inorganic powder such as silica-based fine powder and drying You may. After the completion of the reaction, the concentration can be adjusted if necessary.

[Cement Composition] The cement composition of the present invention contains the cement dispersant of the present invention, cement and water as essential components.

The cement used in the cement composition of the present invention is not particularly limited. For example, Portland cement (ordinary, early-strength, ultra-high-strength, moderate heat, sulfate-resistant and each low alkali type), various mixed cements (blast furnace cement, silica cement, fly ash cement), white Portland cement, alumina cement, Ultra-fast setting cement (1 clinker fast setting cement, 2
Clinker fast-setting cement, magnesium phosphate cement), grout cement, oil well cement, low heat cement (low heat type blast furnace cement, fly ash mixed low heat type blast furnace cement, belite-rich cement), ultra-high strength cement, cement Solidified material, eco-cement (cement made from one or more of municipal solid waste incineration ash, sewage sludge incineration ash) and the like, and blast furnace slag, fly ash, cinder ash, clinker ash, husk ash, silica Fine powder such as fume, silica powder, limestone powder and the like or gypsum may be added.
In addition, as an aggregate, besides gravel, crushed stone, granulated slag, recycled aggregate, etc., siliceous, clay, zircon, high alumina, silicon carbide, graphite, chromium, chromium, magnesia, etc. Can be used.

In the cement composition of the present invention, there are no particular restrictions on the amount of water per 1 m ³ , the amount of cement used, and the water / cement ratio.
85 kg / m ³ , amount of cement used 250-800 kg /
m ³ , water / cement ratio (weight ratio) = 0.1-0.7, preferably unit water amount 120-175 kg / m ³ , cement amount used 270-800 kg / m ³ , water / cement ratio (weight ratio) = 0.2 to 0.65 is recommended, and it can be used widely from poor to rich blends, and is effective for both high-strength concrete with a large amount of cement and poorly-mixed concrete with a unit cement of 300 kg / m ³ or less. It is.

The mixing ratio of the cement dispersant of the present invention in the cement composition of the present invention is not particularly limited. It may be added in an amount of 10 to 10% by weight, preferably 0.02 to 5% by weight, more preferably 0.05 to 3% by weight, and still more preferably 0.1 to 2% by weight. With this addition,
Various favorable effects such as a reduction in the unit water amount, an increase in strength, and an improvement in durability are provided. The mixing ratio is 0.0
If the amount is less than 1% by weight, the performance is insufficient. Conversely, even if a large amount exceeding 10% by weight is used, the effect is substantially flattened, and the economical disadvantage is disadvantageous.

Further, the cement composition of the present invention is effective for concrete for secondary concrete products, centrifugal molding concrete, vibration compaction concrete, steam-cured concrete, shotcrete and the like. It is also effective for mortar and concrete requiring high fluidity such as self-compacting concrete and self-leveling material.

The cement composition of the present invention may contain a known cement dispersant. The known cement dispersant that can be used is not particularly limited, and various sulfonic acid-based dispersants having a sulfonic acid group in the molecule and various polycarboxylic acid-based ones having a polyoxyalkylene chain and a carboxyl group in the molecule are available. And dispersants. Examples of the sulfonic acid-based dispersant include lignin sulfonate; polyol derivative; naphthalenesulfonic acid formalin condensate;
Melaminesulfonic acid formalin condensate; polystyrenesulfonic acid salt; aminoarylsulfonic acid-phenol-
Examples thereof include aminosulfonic acid-based compounds such as formaldehyde condensate. Examples of the polycarboxylic acid dispersant include, for example, a polyalkylene glycol mono (meth) acrylate ester monomer having a polyoxyalkylene chain obtained by adding an alkylene oxide having 2 to 18 carbon atoms in an average addition mole number of 2 to 300. Obtained by copolymerizing a monomer component containing a monomer and a (meth) acrylic acid-based monomer as essential components; an alkylene oxide having 2 to 3 carbon atoms in an average addition mole number of 2 to 300. An essential component is a polyalkylene glycol mono (meth) acrylate monomer having an added polyoxyalkylene chain, and three types of monomers of (meth) acrylic acid monomer and alkyl (meth) acrylate. A copolymer obtained by copolymerizing monomer components containing: a polyalkylene oxide having 2 to 3 carbon atoms and having an average addition mole number of 2 to 300 added Polyalkylene glycol mono (meth) acrylate monomer having xyalkylene chain, (meth) acrylic acid monomer and (meth) allylsulfonic acid (salt) (or vinylsulfonic acid (salt) or p- (Meth) allyloxybenzenesulfonic acid (any of salts)), a copolymer obtained by copolymerizing a monomer component containing three types of monomers as essential components;
A polyalkylene glycol mono (meth) acrylate monomer having a polyoxyalkylene chain to which ethylene oxide has been added in an average addition mole number of 2 to 50, a (meth) acrylic acid monomer and a (meth) allyl sulfonic acid ( (Meth) acrylamide and / or 2- (meth) acrylamide-2-
A copolymer obtained by graft polymerization of methylpropanesulfonic acid; an average addition mole number of a polyethylene glycol mono (meth) acrylate monomer having a polyoxyalkylene chain to which ethylene oxide is added at an average addition mole number of 5 to 50 and ethylene oxide And a (meth) acrylic acid-based monomer having a polyoxyalkylene chain and a (meth) allylsulfonic acid (salt) (or p- (meth) ) Allyloxybenzenesulfonic acid (salt)
A) a copolymer obtained by copolymerizing a monomer component containing the four types of monomers as essential components;
A monomer component comprising, as essential components, a polyalkylene glycol mono (meth) allyl ether-based monomer having a polyoxyalkylene chain obtained by adding an alkylene oxide of 2 to 300 in an average addition mole number and a maleic acid-based monomer A polyalkylene glycol mono (meth) allyl ether-based monomer having a polyoxyalkylene chain obtained by adding an alkylene oxide having 2 to 4 carbon atoms by an average addition mole number of 2 to 300; A copolymer obtained by copolymerizing a monomer component containing a polyalkylene glycol ester monomer of maleic acid as an essential component; an alkylene oxide having 2 to 4 carbon atoms in an average addition mole number of 2
It is obtained by copolymerizing a monomer component containing a polyalkylene glycol 3-methyl-3-butenyl ether-based monomer having a polyoxyalkylene chain and a maleic acid-based monomer to which 300 to 300 has been added as essential components. Copolymer; and the like. The above-mentioned known cement dispersants can be used in combination of two or more.

When the above-mentioned known cement dispersant is used, the compounding weight ratio of the cement dispersant of the present invention to the known cement dispersant depends on the type, composition and test conditions of the known cement dispersant used. Although it cannot be uniquely determined by the difference, it is preferably in the range of 5:95 to 95: 5, more preferably in the range of 10:90 to 90:10.

Further, the cement composition of the present invention can contain other known cement additives (materials) as exemplified in the following (1) to (20). (1) Water-soluble polymer: unsaturated carboxylic acid polymer such as polyacrylic acid (sodium), polymethacrylic acid (sodium), polymaleic acid (sodium), sodium salt of acrylic acid / maleic acid copolymer; methyl Nonionic cellulose ethers such as cellulose, ethyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, carboxyethyl cellulose, and hydroxypropyl cellulose; polysaccharides such as methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose The hydrogen atom of a part or all of the hydroxyl groups of the alkylated or hydroxyalkylated derivative of the above has 8 to 4 carbon atoms.
Polysaccharide derivatives substituted with a hydrophobic substituent having a hydrocarbon chain of 0 as a partial structure and an ionic hydrophilic substituent having a sulfonic acid group or a salt thereof as a partial structure; yeast glucan, xanthan gum, β- 1.3 Polysaccharides produced by microbial fermentation of 3-glucans (either linear or branched, for example, curdlan, paramylon, bakiman, scleroglucan, laminaran, etc.); polyacrylamide Polyvinyl alcohol; starch; starch phosphate; sodium alginate; gelatin; copolymers of acrylic acid having an amino group in the molecule and quaternary compounds thereof. (2) Polymer emulsion: a copolymer of various vinyl monomers such as alkyl (meth) acrylate. (3) retarders: gluconic acid, glucoheptonic acid, arabonic acid, malic acid or citric acid, and oxycarboxylic acids such as inorganic salts or organic salts such as sodium, potassium, calcium, magnesium, ammonium and triethanolamine; Acids; monosaccharides such as glucose, fructose, galactose, saccharose, xylose, abitose, repose, isomerized sugars, oligosaccharides such as disaccharides and trisaccharides, oligosaccharides such as dextrin, and polysaccharides such as dextran; Saccharides such as molasses; sugar alcohols such as sorbitol; magnesium silicofluoride; phosphoric acid and salts or borates thereof; aminocarboxylic acids and salts thereof; alkali-soluble proteins; humic acid; tannic acid; Polyhydric alcohols such as glycerin; Acid), 1-hydroxyethylidene-1,1-diphosphonic acid, ethylenediaminetetra
(Methylene phosphonic acid), diethylene triamine penta
(Methylene phosphonic acid) and their alkali metal salts,
Phosphonic acids such as alkaline earth metal salts and derivatives thereof; (4) Early strength agents and accelerators: Soluble calcium salts such as calcium chloride, calcium nitrite, calcium nitrate, calcium bromide, calcium iodide; chlorides such as iron chloride, magnesium chloride; sulfate; potassium hydroxide; Sodium hydroxide; carbonate; thiosulfate; formate such as formic acid and calcium formate; alkanolamine; alumina cement; calcium aluminate silicate; (5) Mineral oil-based antifoaming agents: kerosene, liquid paraffin and the like. (6) Oil-based antifoaming agents: animal and vegetable oils, sesame oil, castor oil, alkylene oxide adducts thereof and the like. (7) Fatty acid antifoaming agents: oleic acid, stearic acid, alkylene oxide adducts thereof and the like. (8) Fatty acid ester antifoaming agents: glycerin monoricinoleate, alkenyl succinic acid derivatives, sorbitol monolaurate, sorbitol trioleate, natural wax and the like. (9) oxyalkylene antifoaming agents: polyoxyalkylenes such as (poly) oxyethylene (poly) oxypropylene adduct; diethylene glycol heptyl ether;
Polyoxyethylene oleyl ether, polyoxypropylene butyl ether, polyoxyethylene polyoxypropylene 2-ethylhexyl ether, having 12 to 12 carbon atoms
(Poly) oxyalkyl ethers such as oxyethyleneoxypropylene adducts to higher alcohols of No. 14; (poly) oxyalkylene (alkyl) aryl ethers such as polyoxypropylene phenyl ether and polyoxyethylene nonylphenyl ether; 4,7,9
-Tetramethyl-5-decyne-4,7-diol, 2,
5-dimethyl-3-hexyne-2,5-diol, 3-
Acetylene ethers obtained by addition-polymerizing an alkylene oxide to an acetylene alcohol such as methyl-1-butyn-3-ol; (poly) oxyalkylene fatty acid esters such as diethylene glycol oleate, diethylene glycol laurate, and ethylene glycol distearate (Poly) oxyalkylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monolaurate and polyoxyethylene sorbitan trioleate; (poly) such as sodium polyoxypropylene methyl ether sulfate and sodium polyoxyethylene dodecyl phenol ether sulfate Oxyalkylene alkyl (aryl) ether sulfates; (poly) oxyethylene stearyl phosphate, etc. (Poly) oxyalkylene alkyl phosphoric acid esters; polyoxyethylene such as polyoxyethylene lauryl amine (poly) oxyalkylene alkyl amines; polyoxyalkylene amide. (10) Alcohol antifoaming agents: octyl alcohol, hexadecyl alcohol, acetylene alcohol, glycols and the like. (11) Amide-based antifoaming agent: acrylate polyamine and the like. (12) Phosphate ester antifoam: tributyl phosphate,
Sodium octyl phosphate and the like. (13) Metal soap-based antifoaming agents: aluminum stearate, calcium oleate and the like. (14) silicone antifoaming agent: dimethyl silicone oil,
Silicone paste, silicone emulsion, organically modified polysiloxane (polyorganosiloxane such as dimethylpolysiloxane), fluorosilicone oil and the like. (15) AE agent: resin soap, saturated or unsaturated fatty acid,
Sodium hydroxystearate, lauryl sulfate, ABS (alkylbenzene sulfonic acid), LAS (linear alkylbenzene sulfonic acid), alkane sulfonate, polyoxyethylene alkyl (phenyl) ether, polyoxyethylene alkyl (phenyl) ether sulfate or a salt thereof, Polyoxyethylene alkyl (phenyl) ether phosphate or a salt thereof, a protein material, alkenyl sulfosuccinic acid, α-olefin sulfonate and the like. (16) Other surfactants: aliphatic monohydric alcohols having 6 to 30 carbon atoms in a molecule such as octadecyl alcohol and stearyl alcohol, and 6 to 30 carbon atoms in a molecule such as abiethyl alcohol Alicyclic 1
6 to 6 in the molecule of polyhydric alcohol, dodecyl mercaptan, etc.
Monovalent mercaptans having 30 carbon atoms, nonylphenols, etc., alkylphenols having 6 to 30 carbon atoms, dodecylamines, etc. having 6 to 3 carbon atoms in the molecule.
Polyalkylene oxide obtained by adding an alkylene oxide such as ethylene oxide or propylene oxide by 10 mol or more to a carboxylic acid having 6 to 30 carbon atoms in a molecule such as an amine having 0 carbon atoms, lauric acid or stearic acid. Derivatives; alkyl diphenyl ether sulfonates, which may have an alkyl group or an alkoxy group as a substituent, and two phenyl groups having a sulfone group are ether-bonded; various anionic surfactants; alkyl amine acetates, alkyl amines Various cationic surfactants such as trimethylammonium chloride; various nonionic surfactants; various amphoteric surfactants and the like. (17) Waterproofing agents: fatty acids (salts), fatty acid esters, oils and fats, silicon, paraffin, asphalt, wax and the like. (18) Rust inhibitors: nitrites, phosphates, zinc oxide and the like. (19) Crack reducing agent: polyoxyalkyl ether and the like. (20) Expansive materials: ettringite, coal, etc.

Other known cement additives (materials) include, for example, cement wetting agents, thickening agents, separation reducing agents, coagulants, drying shrinkage reducing agents, strength enhancers, self-leveling agents, rust inhibitors, Coloring agents, fungicides and the like can be mentioned. The above-mentioned known cement additives (materials) may be used in combination of two or more.

In the cement composition of the present invention, particularly preferred embodiments of components other than cement and water include the following 1) to 7).

1) Combination essentially comprising two components of the cement dispersant of the present invention and an oxyalkylene-based antifoaming agent.
The weight ratio of the oxyalkylene-based antifoaming agent is preferably in the range of 0.01 to 10% by weight based on the cement dispersant.

2) The cement dispersant of the present invention, the alkylene oxide having 2 to 18 carbon atoms, having an average addition mole number of 2 to 2
A polyalkylene glycol mono (meth) acrylate monomer having a 300-added polyoxyalkylene chain, a (meth) acrylic acid monomer and a monomer copolymerizable with these monomers A combination in which three components of a copolymer (see JP-B-59-18338, JP-A-7-223852, JP-A-9-241056, etc.) and an oxyalkylene-based antifoaming agent are essential.
The compounding weight ratio of the copolymer with the cement dispersant is preferably in the range of 5:95 to 95: 5, preferably 1:95 to 95: 5.
The range of 0:90 to 90:10 is more preferable. The weight ratio of the oxyalkylene-based antifoaming agent is 0.01% based on the total amount of the copolymer with the cement dispersant.
A range of from 10 to 10% by weight is preferred.

3) Combination essentially comprising two components of the cement dispersant of the present invention and a sulfonic acid-based dispersant having a sulfonic acid group in the molecule. As a sulfonic acid-based dispersant,
Aminosulfonic acid-based dispersants such as ligninsulfonic acid salt, naphthalenesulfonic acid formalin condensate, melaminesulfonic acid formalin condensate, polystyrenesulfonic acid salt, and aminoarylsulfonic acid-phenol-formaldehyde condensate can be used. The mixing weight ratio of the cement dispersant to the sulfonic acid dispersant is preferably in the range of 5:95 to 95: 5, and is preferably 10:90.
The range of -90: 10 is more preferable.

4) A combination comprising two components of the cement dispersant of the present invention and lignin sulfonate. The compounding weight ratio of the cement dispersant to the lignin sulfonate is preferably in the range of 5:95 to 95: 5, more preferably in the range of 10:90 to 90:10.

5) Combination of two essential components of the cement dispersant of the present invention and the material separation reducing agent. Examples of the material separation reducing agent include various thickeners such as nonionic cellulose ethers, and the average addition of a hydrophobic substituent composed of a hydrocarbon chain having 4 to 30 carbon atoms and an alkylene oxide having 2 to 18 carbon atoms as a partial structure. A compound having a polyoxyalkylene chain added with 2 to 300 moles can be used.
The compounding weight ratio of the cement dispersant to the material separation reducing agent is 10:90 to 99.99: 0.01.
Is preferable, and the range of 50:50 to 99.9: 0.1 is more preferable. A cement composition comprising this combination is suitable as a high fluidity concrete, a self-compacting concrete, and a self-leveling material.

6) Combination of two essential components of the cement dispersant and retarder of the present invention. Examples of the retarder include oxycarboxylic acids such as gluconic acid (salt) and citric acid (salt), sugars such as glucose, sugar alcohols such as sorbitol, and phosphonic acids such as aminotri (methylenephosphonic acid). . In addition, as a compounding weight ratio of the cement dispersant and the retarder, 50:50 to 9
The range of 9.9: 0.1 is preferable, and 70:30 to 99:
A range of 1 is more preferred.

7) Combination of two essential components of the cement dispersant and the accelerator of the present invention. As the accelerator, soluble calcium salts such as calcium chloride, calcium nitrite, and calcium nitrate, chlorides such as iron chloride and magnesium chloride, and thiosulfates, formates such as formic acid and calcium formate can be used. The mixing weight ratio between the cement dispersant and the accelerator was 10:90 to 9
The range of 9.9: 0.1 is preferred, and 20:80 to 99:
A range of 1 is more preferred.

[0102]

The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the present invention is limited thereto. In the examples and tables, unless otherwise specified, "%" represents% by weight, and "parts" represents parts by weight.

In the Production Examples, the amount of polyalkylene glycol produced as a by-product during the production of the unsaturated polyalkylene glycol ether-based monomer was measured under the following conditions.

<Measurement Conditions of Polyalkylene Glycol Generation Amount> Model: Shimadzu Corporation LC-10 Detector: Differential refractometer (RI) detector (HITACHI)
3350 RI MONITOR) Eluent: Kind Ion-exchanged water Flow rate 1.5 ml / min Column: Kind “Showex GF- manufactured by Showa Denko KK”
310 "4.6 × 300 mm Temperature 40 ° C. The reaction rate of each monomer in the examples and the weight average molecular weight of the obtained copolymer were measured under the following conditions.

<Conditions for measuring the reaction rate of each raw material monomer> Model: JASCO CORPORATION Borwin Detector: Differential refractometer (RI) detector (HITACHI)
3350 RI MONITOR) Eluent: type Acetonitrile / 0.1% phosphate ion exchange aqueous solution = 50/50 (vol%) Flow rate 1.0 ml / min Column: Type "ODS-120T + O" manufactured by Tosoh Corporation
DS-80Ts "4.6 × 250 mm each Temperature 40 ° C. <Measurement conditions of weight average molecular weight of copolymer> Model: Waters LCM1 Detector: Differential refractometer (RI) detector (Waters 41)
0) Eluent: type 0.05 M sodium acetate, acetonitrile / ion exchange aqueous solution = 40/60 (vol%), adjusted to pH 6.0 with acetic acid Flow rate 0.6 ml / min Column: type "TSK-" manufactured by Tosoh Corporation GEL G4
000SWXL "+" G3000SWXL "+" G20
00SWXL + GUARD COLUMN "7.8x each
300 mm, 6.0 × 40 mm Temperature 40 ° C. Calibration curve: polyethylene glycol standard <Production Example 1> A methallyl alcohol (as an unsaturated alcohol) was placed in a stainless steel high-pressure reactor equipped with a thermometer, a stirrer, nitrogen, and an alkylene oxide introduction tube. 2-methyl-2
196 parts of (propen-1-ol) and 3.1 parts of sodium hydroxide as an addition reaction catalyst were charged, the inside of the reaction vessel was replaced with nitrogen under stirring, and heated to 150 ° C under a nitrogen atmosphere. Then, 6310 parts of ethylene oxide were introduced into the reactor while maintaining 150 ° C. under a safe pressure, and the temperature was maintained until the alkylene oxide addition reaction was completed to complete the reaction. The obtained reaction product (hereinafter, referred to as M-1) is an unsaturated polyalkylene glycol ether-based monomer obtained by adding an average of 50 mol of ethylene oxide to methallyl alcohol (hereinafter, referred to as MAL-50). In addition, a polyalkylene glycol (polyethylene glycol) was contained as a by-product, and the amount of polyethylene glycol produced was 5.0% based on the amount of the unsaturated polyalkylene glycol ether-based monomer.

<Production Examples 2 to 7> The procedure of Production Example 1 was repeated except that the types and amounts of the unsaturated alcohol, the sodium hydroxide as the addition reaction catalyst, and the alkylene oxide were changed as shown in Table 1. An alkylene oxide addition reaction was performed on the unsaturated alcohol to obtain reaction products (M2) to (M7) containing the unsaturated polyalkylene glycol ether-based monomer and the polyalkylene glycol. In addition, all alkylene oxide addition reactions are performed at 150 ° C., and when two types of alkylene oxides, ethylene oxide and propylene oxide, are used, first, the entire amount of propylene oxide is added to the unsaturated alcohol, and then ethylene oxide is added. Thus, a block-shaped adduct was obtained. Table 1 shows the amount of by-product polyalkylene glycol produced with respect to the unsaturated polyalkylene glycol ether-based monomer in the obtained reaction product.

[0107]

[Table 1]

Example 1 A glass reactor equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser was charged with 280 parts of ion-exchanged water and the reaction product (M) obtained in Production Example 1. -1) 420 parts (MAL-50 is 400
Parts, containing 20 parts of polyethylene glycol)
The temperature was raised to 65 ° C. With the reaction vessel kept at 65 ° C,
An aqueous hydrogen peroxide solution consisting of 0.564 parts of hydrogen peroxide and 10.72 parts of ion-exchanged water was added. After maintaining the temperature at 65 ° C. for 30 minutes after charging the aqueous hydrogen peroxide solution, methacrylic acid 5
6.2 parts were dropped into the reaction vessel over 3 hours, and at the same time, an aqueous solution in which 0.731 part of L-ascorbic acid was dissolved in 13.88 parts of ion-exchanged water was dropped over 3.5 hours. Thereafter, the temperature was maintained at 65 ° C. for 1 hour to complete the polymerization reaction. The concentration of the polymerization components (weight% concentration of all monomer components with respect to all raw materials) was 60%. Thereafter, the reaction solution was neutralized to pH 7 using an aqueous sodium hydroxide solution at a temperature equal to or lower than the polymerization reaction temperature to obtain a cement dispersant (D1) of the present invention.

The conversion (%) of each raw material monomer, the copolymer composition ratio (%) of the copolymer contained in the obtained dispersant, and the amount of the structural unit derived from the unsaturated polyalkylene glycol ether monomer (Mol%), amount of carboxylic acid in terms of unneutralized copolymer (meq / g), weight average molecular weight, content of unsaturated polyalkylene glycol ether-based monomer relative to neutralized copolymer (%) Table 2 shows the content (%) of the polyalkylene glycol relative to the neutralized copolymer.

Example 2 In a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser, 278 parts of ion-exchanged water, the reaction product (M -1) 420 parts (MAL-50 is 400
Parts, containing 20 parts of polyethylene glycol)
The temperature was raised to 65 ° C. With the reaction vessel kept at 65 ° C,
An aqueous hydrogen peroxide solution consisting of 0.597 parts of hydrogen peroxide and 11.35 parts of ion-exchanged water was added. After maintaining the temperature at 65 ° C. for 30 minutes after charging the aqueous hydrogen peroxide solution, methacrylic acid 2
Put 8.1 parts and 27.0 parts of acrylic acid in a reaction vessel
13. dripping over time, and at the same time, ion-exchanged water;
An aqueous solution in which 0.773 part of L-ascorbic acid and 0.932 part of 3-mercaptopropionic acid were dissolved in 70 parts was dropped over 3.5 hours. Thereafter, the temperature was maintained at 65 ° C. for 1 hour to complete the polymerization reaction. In addition,
The concentration of the polymerization components (the concentration by weight of all monomer components with respect to all raw materials) was 60%. Thereafter, the reaction solution was adjusted to pH 7 using an aqueous solution of sodium hydroxide at a temperature lower than the polymerization reaction temperature.
To obtain a cement dispersant (D2) of the present invention.

The reaction rate (%) of each raw material monomer, the copolymer composition ratio (%) of the copolymer contained in the obtained dispersant, the amount of the structural unit derived from the unsaturated polyalkylene glycol ether monomer (Mol%), amount of carboxylic acid in terms of unneutralized copolymer (meq / g), weight average molecular weight, content of unsaturated polyalkylene glycol ether-based monomer relative to neutralized copolymer (%) Table 2 shows the content (%) of the polyalkylene glycol relative to the neutralized copolymer.

Example 3 129 parts of ion-exchanged water, a reaction product (M -2) 421 parts (MAL-75 400
Parts, containing 21 parts of polyethylene glycol)
The temperature was raised to 65 ° C. With the reaction vessel kept at 65 ° C,
An aqueous hydrogen peroxide solution consisting of 0.440 parts of hydrogen peroxide and 8.37 parts of ion-exchanged water was added. After maintaining the temperature at 65 ° C. for 30 minutes after the introduction of the aqueous hydrogen peroxide solution, methacrylic acid 4
5.5 parts was dropped into the reaction vessel over 3 hours, and at the same time, an aqueous solution in which 0.570 parts of L-ascorbic acid was dissolved in 10.84 parts of ion-exchanged water was dropped over 3.5 hours. Thereafter, the temperature was maintained at 65 ° C. for 1 hour to complete the polymerization reaction. Incidentally, the concentration of the polymerization component (the concentration by weight of all monomer components with respect to all raw materials) was 75%. Thereafter, the reaction solution was neutralized to pH 7 using an aqueous sodium hydroxide solution at a temperature not higher than the polymerization reaction temperature to obtain a cement dispersant (D3) of the present invention.

The reaction rate (%) of each raw material monomer, the copolymer composition ratio (%) of the copolymer contained in the obtained dispersant, the amount of the structural unit derived from the unsaturated polyalkylene glycol ether monomer (Mol%), amount of carboxylic acid in terms of unneutralized copolymer (meq / g), weight average molecular weight, content of unsaturated polyalkylene glycol ether monomer based on neutralized copolymer (%) Table 2 shows the content (%) of the polyalkylene glycol relative to the neutralized copolymer.

Example 4 A glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser was charged with 121 parts of ion-exchanged water and the reaction product (M -3) 426 parts (MAL-100 is 400
Parts, containing 26 parts of polyethylene glycol)
The temperature was raised to 65 ° C. With the reaction vessel kept at 65 ° C,
An aqueous solution of hydrogen peroxide consisting of 0.618 parts of hydrogen peroxide and 11.74 parts of ion-exchanged water was added. After maintaining the temperature at 65 ° C. for 30 minutes after the introduction of the aqueous hydrogen peroxide solution, methacrylic acid 1
8.2 parts and 43.8 parts of acrylic acid were placed in a reaction vessel 3
14. Drops over time, and at the same time, ion-exchanged water
An aqueous solution in which 0.801 part of L-ascorbic acid and 0.965 part of 3-mercaptopropionic acid were dissolved in 21 parts was dropped over 3.5 hours. Thereafter, the temperature was maintained at 65 ° C. for 1 hour to complete the polymerization reaction. In addition,
The concentration of the polymerization component (concentration by weight of all monomer components with respect to all raw materials) was 75%. Thereafter, the reaction solution was adjusted to pH 7 using an aqueous solution of sodium hydroxide at a temperature lower than the polymerization reaction temperature.
To obtain a cement dispersant (D4) of the present invention.

The reaction rate (%) of each raw material monomer, the copolymer composition ratio (%) of the copolymer contained in the obtained dispersant, and the amount of the structural unit derived from the unsaturated polyalkylene glycol ether monomer (Mol%), amount of carboxylic acid in terms of unneutralized copolymer (meq / g), weight average molecular weight, content of unsaturated polyalkylene glycol ether monomer based on neutralized copolymer (%) Table 2 shows the content (%) of the polyalkylene glycol relative to the neutralized copolymer.

Example 5 A glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen introducing tube and a reflux condenser was charged with 115 parts of ion-exchanged water and the reaction product (M -4) 448 parts (400 for MAL-200)
Parts, containing 48 parts of polyethylene glycol)
The temperature was raised to 65 ° C. With the reaction vessel kept at 65 ° C,
An aqueous hydrogen peroxide solution comprising 0.838 parts of hydrogen peroxide and 15.91 parts of ion-exchanged water was added. After maintaining the temperature at 65 ° C. for 30 minutes after the introduction of the aqueous hydrogen peroxide solution, methacrylic acid 3
7.5 parts and 54.1 parts of acrylic acid were placed in a reaction vessel 3
Drop over time, and at the same time, ion-exchanged water 20.
An aqueous solution in which 1.085 part of L-ascorbic acid and 0.654 part of 3-mercaptopropionic acid were dissolved in 61 parts was dropped over 3.5 hours. Thereafter, the temperature was maintained at 65 ° C. for 1 hour to complete the polymerization reaction. In addition,
The concentration of the polymerization component (concentration by weight of all monomer components with respect to all raw materials) was 75%. Thereafter, the reaction solution was adjusted to pH 7 using an aqueous solution of sodium hydroxide at a temperature lower than the polymerization reaction temperature.
To obtain a cement dispersant (D5) of the present invention.

The conversion (%) of each raw material monomer, the copolymer composition ratio (%) of the copolymer contained in the obtained dispersant, and the amount of the structural unit derived from the unsaturated polyalkylene glycol ether-based monomer (Mol%), amount of carboxylic acid in terms of unneutralized copolymer (meq / g), weight average molecular weight, content of unsaturated polyalkylene glycol ether-based monomer relative to neutralized copolymer (%) Table 2 shows the content (%) of the polyalkylene glycol relative to the neutralized copolymer.

Example 6 A glass reactor equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser was charged with 285 parts of ion-exchanged water and the reaction product (M) obtained in Production Example 1. -1) 420 parts (MAL-50 is 400
Parts, containing 20 parts of polyethylene glycol)
The temperature was raised to 65 ° C. With the reaction vessel kept at 65 ° C,
An aqueous hydrogen peroxide solution consisting of 0.649 parts of hydrogen peroxide and 12.33 parts of ion-exchanged water was added. After maintaining the temperature at 65 ° C. for 30 minutes after charging the aqueous hydrogen peroxide solution, methacrylic acid 5
7.9 parts and 2-hydroxyethyl acrylate 1
2.1 parts were dropped into the reaction vessel over 3 hours, and at the same time, an aqueous solution in which 0.840 parts of L-ascorbic acid was dissolved in 15.96 parts of ion-exchanged water was dropped over 3.5 hours. Thereafter, the temperature was maintained at 65 ° C. for 1 hour to complete the polymerization reaction. The concentration of the polymerization components (weight% concentration of all monomer components with respect to all raw materials) was 60%. Thereafter, the reaction solution was neutralized to pH 7 using an aqueous sodium hydroxide solution at a temperature equal to or lower than the polymerization reaction temperature to obtain a cement dispersant (D6) of the present invention.

The reaction rate (%) of each raw material monomer, the copolymer composition ratio (%) of the copolymer contained in the obtained dispersant, the amount of the structural unit derived from the unsaturated polyalkylene glycol ether monomer (Mol%), amount of carboxylic acid in terms of unneutralized copolymer (meq / g), weight average molecular weight, content of unsaturated polyalkylene glycol ether monomer based on neutralized copolymer (%) Table 2 shows the content (%) of the polyalkylene glycol relative to the neutralized copolymer.

Example 7 A glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser was charged with 278 parts of ion-exchanged water and the reaction product (M) obtained in Production Example 5. -5) 422 parts (MAL-70EO5PO)
Was added to the mixture, and the mixture was heated to 65 ° C. While the reaction vessel was maintained at 65 ° C., an aqueous hydrogen peroxide solution containing 0.439 parts of hydrogen peroxide and 8.34 parts of ion-exchanged water was added. After maintaining the temperature at 65 ° C. for 30 minutes after charging the aqueous hydrogen peroxide solution, 45.5 parts of methacrylic acid was dropped into the reaction vessel over 3 hours, and at the same time, L-ascorbic acid was added to 10.80 parts of ion-exchanged water in 0.10 parts. An aqueous solution in which 568 parts were dissolved was added dropwise over 3.5 hours. Thereafter, the temperature was maintained at 65 ° C. for 1 hour to complete the polymerization reaction. In addition,
The concentration of the polymerization components (the concentration by weight of all monomer components with respect to all raw materials) was 60%. Thereafter, the reaction solution was adjusted to pH 7 using an aqueous solution of sodium hydroxide at a temperature lower than the polymerization reaction temperature.
To obtain a cement dispersant (D7) of the present invention.

The conversion (%) of each raw material monomer, the copolymer composition ratio (%) of the copolymer contained in the obtained dispersant, and the amount of the structural unit derived from the unsaturated polyalkylene glycol ether-based monomer (Mol%), amount of carboxylic acid in terms of unneutralized copolymer (meq / g), weight average molecular weight, content of unsaturated polyalkylene glycol ether monomer based on neutralized copolymer (%) Table 2 shows the content (%) of the polyalkylene glycol relative to the neutralized copolymer.

Example 8 A glass reactor equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser was charged with 88 parts of ion-exchanged water and the reaction product (M -6) Charge 410 parts (containing 400 parts of AL-50 and 10 parts of polyethylene glycol) at 80 ° C.
The temperature rose. With the reaction vessel kept at 80 ° C., an aqueous hydrogen peroxide solution comprising 2.257 parts of hydrogen peroxide and 9.03 parts of ion-exchanged water was added. After maintaining the temperature at 80 ° C. for 30 minutes after charging the aqueous hydrogen peroxide solution, 56.2 parts of methacrylic acid was dropped into the reaction vessel over 3 hours, and at the same time, L-ascorbic acid was added to 16.56 parts of ion-exchanged water. 92
An aqueous solution in which 3 parts were dissolved was added dropwise over 3.5 hours.
Thereafter, the temperature was maintained at 80 ° C. continuously for 1 hour to complete the polymerization reaction. Incidentally, the concentration of the polymerization component (the concentration by weight of all the monomer components with respect to all the raw materials) was 80%. Thereafter, the reaction solution was neutralized to pH 7 using an aqueous sodium hydroxide solution at a temperature equal to or lower than the polymerization reaction temperature to obtain a cement dispersant (D8) of the present invention.

The reaction rate (%) of each raw material monomer, the copolymer composition ratio (%) of the copolymer contained in the obtained dispersant, the amount of the structural unit derived from the unsaturated polyalkylene glycol ether monomer (Mol%), amount of carboxylic acid in terms of unneutralized copolymer (meq / g), weight average molecular weight, content of unsaturated polyalkylene glycol ether-based monomer relative to neutralized copolymer (%) Table 2 shows the content (%) of the polyalkylene glycol relative to the neutralized copolymer.

Example 9 In a glass reactor equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser, 86 parts of ion-exchanged water, the reaction product obtained in Production Example 6 (M -6) Charge 410 parts (containing 400 parts of AL-50 and 10 parts of polyethylene glycol) at 80 ° C.
The temperature rose. With the reaction vessel kept at 80 ° C., an aqueous hydrogen peroxide solution consisting of 2.433 parts of hydrogen peroxide and 9.73 parts of ion-exchanged water was added. After maintaining the temperature at 80 ° C. for 30 minutes after charging the aqueous hydrogen peroxide solution, 18.7 parts of methacrylic acid and 36.0 parts of acrylic acid were dropped into the reaction vessel over 3 hours, and at the same time, 17.86 parts of ion-exchanged water An aqueous solution in which 3.151 parts of L-ascorbic acid and 0.475 part of 3-mercaptopropionic acid are dissolved in 3.5 parts of
It was dropped over time. After that, continue for 1 hour at 80 ° C
And the polymerization reaction was completed. The concentration of the polymerization component (concentration of the weight ratio of all monomer components to all raw materials) was 8%.
It was 0%. Thereafter, the reaction solution was neutralized to pH 7 using an aqueous solution of sodium hydroxide at a temperature not higher than the polymerization reaction temperature to obtain a cement dispersant (D9) of the present invention.

The reaction rate (%) of each raw material monomer, the copolymer composition ratio (%) of the copolymer contained in the obtained dispersant, the amount of the structural unit derived from the unsaturated polyalkylene glycol ether monomer (Mol%), amount of carboxylic acid in terms of unneutralized copolymer (meq / g), weight average molecular weight, content of unsaturated polyalkylene glycol ether-based monomer relative to neutralized copolymer (%) Table 2 shows the content (%) of the polyalkylene glycol relative to the neutralized copolymer.

Example 10 A glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser was charged with 91 parts of ion-exchanged water and the reaction product (M -7) Charge 413 parts (containing 400 parts of AL-75 and 13 parts of polyethylene glycol) at 80 ° C.
The temperature rose. With the reaction vessel kept at 80 ° C., an aqueous solution of hydrogen peroxide consisting of 1.762 parts of hydrogen peroxide and 7.05 parts of ion-exchanged water was added. After maintaining the temperature at 80 ° C. for 30 minutes after charging the aqueous hydrogen peroxide solution, 45.5 parts of methacrylic acid was dropped into the reaction vessel over 3 hours. 28
An aqueous solution in which 2 parts were dissolved was added dropwise over 3.5 hours.
Thereafter, the temperature was maintained at 80 ° C. continuously for 1 hour to complete the polymerization reaction. Incidentally, the concentration of the polymerization component (the concentration by weight of all the monomer components with respect to all the raw materials) was 80%. Thereafter, the reaction solution was neutralized to pH 7 using an aqueous solution of sodium hydroxide at a temperature lower than the polymerization reaction temperature to obtain a cement dispersant (D10) of the present invention.

The reaction rate (%) of each raw material monomer, the copolymer composition ratio (%) of the copolymer contained in the obtained dispersant, the amount of the structural unit derived from the unsaturated polyalkylene glycol ether monomer (Mol%), amount of carboxylic acid in terms of unneutralized copolymer (meq / g), weight average molecular weight, content of unsaturated polyalkylene glycol ether monomer based on neutralized copolymer (%) Table 2 shows the content (%) of the polyalkylene glycol relative to the neutralized copolymer.

Example 11 In a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser, 85 parts of ion-exchanged water, the reaction product (M -7) Charge 413 parts (containing 400 parts of AL-75 and 13 parts of polyethylene glycol) at 80 ° C.
The temperature rose. While the reaction vessel was maintained at 80 ° C., an aqueous solution of hydrogen peroxide consisting of 2.264 parts of hydrogen peroxide and 9.06 parts of ion-exchanged water was added. After maintaining the temperature at 80 ° C. for 30 minutes after charging the aqueous hydrogen peroxide solution, 9.1 parts of methacrylic acid and 43.8 parts of acrylic acid were dropped into the reaction vessel over 3 hours, and at the same time, 16.61 parts of ion-exchanged water were added. To L
An aqueous solution in which 2.932 parts of ascorbic acid and 0.442 part of 3-mercaptopropionic acid were added dropwise over 3.5 hours. Thereafter, the temperature was maintained at 80 ° C. continuously for 1 hour to complete the polymerization reaction. Incidentally, the concentration of the polymerization component (the concentration by weight of all monomer components with respect to all raw materials) is 80%.
%Met. Thereafter, the reaction solution was neutralized to pH 7 using an aqueous sodium hydroxide solution at a temperature equal to or lower than the polymerization reaction temperature,
Thus, a cement dispersant (D11) of the present invention was obtained.

The reaction rate (%) of each raw material monomer, the copolymer composition ratio (%) of the copolymer contained in the obtained dispersant, the amount of the structural unit derived from the unsaturated polyalkylene glycol ether monomer (Mol%), amount of carboxylic acid in terms of unneutralized copolymer (meq / g), weight average molecular weight, content of unsaturated polyalkylene glycol ether-based monomer relative to neutralized copolymer (%) Table 2 shows the content (%) of the polyalkylene glycol relative to the neutralized copolymer.

Example 12 In a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser, 88 parts of ion-exchanged water, the reaction product obtained in Production Example 7 (M -7) Charge 413 parts (containing 400 parts of AL-75 and 13 parts of polyethylene glycol) at 80 ° C.
The temperature rose. While the reaction vessel was maintained at 80 ° C., an aqueous hydrogen peroxide solution containing 2.055 parts of hydrogen peroxide and 8.22 parts of ion-exchanged water was added. After maintaining the temperature at 80 ° C. for 30 minutes after charging the aqueous hydrogen peroxide solution, 7.2 parts of methacrylic acid,
31.3 parts of acrylic acid and 13.6 parts of 2-hydroxyethyl acrylate were dropped into the reaction vessel over 3 hours, and at the same time, 2.662 parts and 3662 parts of L-ascorbic acid were added to 15.08 parts of ion-exchanged water. -An aqueous solution in which 0.401 parts of mercaptopropionic acid was dissolved was added dropwise over 3.5 hours. Thereafter, the temperature was maintained at 80 ° C. continuously for 1 hour to complete the polymerization reaction. The concentration of the polymerization component (concentration by weight of all monomer components with respect to all raw materials) is 80%.
Met. Thereafter, the reaction solution was neutralized to pH 7 using an aqueous sodium hydroxide solution at a temperature equal to or lower than the polymerization reaction temperature to obtain a cement dispersant (D12) of the present invention.

The reaction rate (%) of each raw material monomer, the copolymer composition ratio (%) of the copolymer contained in the obtained dispersant, the amount of the structural unit derived from the unsaturated polyalkylene glycol ether monomer (Mol%), amount of carboxylic acid in terms of unneutralized copolymer (meq / g), weight average molecular weight, content of unsaturated polyalkylene glycol ether-based monomer relative to neutralized copolymer (%) Table 2 shows the content (%) of the polyalkylene glycol relative to the neutralized copolymer.

<Comparative Example 1> To a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser, 1110 parts of ion-exchanged water and 50 mol of ethylene oxide were added on average to methallyl alcohol. 200 parts of an unsaturated polyalkylene glycol ether-based monomer (not including polyalkylene glycol) was charged and heated to 65 ° C. While the reaction vessel was maintained at 65 ° C., an aqueous hydrogen peroxide solution comprising 0.839 parts of hydrogen peroxide and 15.94 parts of ion-exchanged water was added. 3 after injection of aqueous hydrogen peroxide solution
After maintaining at 65 ° C. for 0 minutes, 98.5 parts of methacrylic acid was dropped into the reaction vessel over 3 hours, and at the same time, 1.086 parts of L-ascorbic acid was added to 20.64 parts of ion-exchanged water.
And an aqueous solution in which 0.655 part of 3-mercaptopropionic acid was dissolved was added dropwise over 3.5 hours. afterwards,
Subsequently, the temperature was maintained at 65 ° C. for 1 hour to complete the polymerization reaction. The concentration of the polymerization components (weight% concentration of all monomer components with respect to all raw materials) was 20%. Thereafter, the reaction solution was neutralized to pH 7 using an aqueous solution of sodium hydroxide at a temperature lower than the polymerization reaction temperature, and a comparative cement dispersant (DC
1) was obtained.

The conversion (%) of each raw material monomer, the copolymer composition ratio (%) of the copolymer contained in the obtained dispersant, and the amount of the structural unit derived from the unsaturated polyalkylene glycol ether monomer (Mol%), amount of carboxylic acid in terms of unneutralized copolymer (meq / g), weight average molecular weight, content of unsaturated polyalkylene glycol ether-based monomer relative to neutralized copolymer (%) Table 3 shows the content (%) of the polyalkylene glycol relative to the neutralized copolymer.

Comparative Example 2 In a glass reactor equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser, 916 parts of ion-exchanged water, 25 mol of ethylene oxide and 25 mol of 200 parts of an unsaturated polyalkylene glycol ether-based monomer (not including polyalkylene glycol) to which propylene oxide was added in moles was charged, and the temperature was raised to 65 ° C. While the reaction vessel was maintained at 65 ° C., an aqueous hydrogen peroxide solution containing 0.307 parts of hydrogen peroxide and 5.84 parts of ion-exchanged water was added. After maintaining the temperature at 65 ° C. for 30 minutes after charging the aqueous hydrogen peroxide solution, 32.3 parts of methacrylic acid was dropped into the reaction vessel over 3 hours, and at the same time, 7.56 parts of ion-exchanged water was added to 0.5% of L-ascorbic acid. An aqueous solution in which 398 parts were dissolved was added dropwise over 3.5 hours. Thereafter, the temperature was maintained at 65 ° C. for 1 hour to complete the polymerization reaction. In addition,
The concentration of the polymerization component (weight% concentration of all monomer components with respect to all raw materials) was 20%. Thereafter, the reaction solution was adjusted to pH 7 using an aqueous solution of sodium hydroxide at a temperature lower than the polymerization reaction temperature.
And a comparative cement dispersant (DC2) was obtained.

The conversion (%) of each raw material monomer, the copolymer composition ratio (%) of the copolymer contained in the obtained dispersant, and the amount of the structural unit derived from the unsaturated polyalkylene glycol ether monomer (Mol%), amount of carboxylic acid in terms of unneutralized copolymer (meq / g), weight average molecular weight, content of unsaturated polyalkylene glycol ether-based monomer relative to neutralized copolymer (%) Table 3 shows the content (%) of the polyalkylene glycol relative to the neutralized copolymer.

Comparative Example 3 A glass reactor equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser was charged with 897 parts of ion-exchanged water and allyl alcohol to which an average of 25 mol of ethylene oxide was added. 200 parts of a saturated polyalkylene glycol ether-based monomer (not including polyalkylene glycol) was charged and heated to 80 ° C. With the reaction vessel kept at 80 ° C.,
An aqueous hydrogen peroxide solution consisting of 353 parts and 5.41 parts of ion-exchanged water was added. After maintaining the temperature at 80 ° C. for 30 minutes after charging the aqueous hydrogen peroxide solution, 28.1 parts of methacrylic acid was dropped into the reaction vessel over 3 hours, and at the same time, L-ascorbic acid was added to 9.93 parts of ion-exchanged water. An aqueous solution in which 752 parts were dissolved was added dropwise over 3.5 hours. Then 1
Subsequently, the temperature was maintained at 80 ° C. to complete the polymerization reaction. The concentration of the polymerization components (weight% concentration of all monomer components with respect to all raw materials) was 20%. Thereafter, the reaction solution was neutralized to pH 7 using an aqueous solution of sodium hydroxide at a temperature lower than the polymerization reaction temperature, and a comparative cement dispersant (DC3) was used.
I got

The reaction rate (%) of each raw material monomer, the copolymer composition ratio (%) of the copolymer contained in the obtained dispersant, the amount of the structural unit derived from the unsaturated polyalkylene glycol ether monomer (Mol%), amount of carboxylic acid in terms of unneutralized copolymer (meq / g), weight average molecular weight, content of unsaturated polyalkylene glycol ether-based monomer relative to neutralized copolymer (%) Table 3 shows the content (%) of the polyalkylene glycol relative to the neutralized copolymer.

Comparative Example 4 In a glass reactor equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser, 898 parts of ion-exchanged water, an average of 20 moles of ethylene oxide and an average of 10 moles in allyl alcohol were used. And 200 parts of an unsaturated polyalkylene glycol ether-based monomer (not including polyalkylene glycol) to which propylene oxide was added, and the temperature was raised to 80 ° C. While the reaction vessel was maintained at 80 ° C., an aqueous hydrogen peroxide solution comprising 1.244 parts of hydrogen peroxide and 4.98 parts of ion-exchanged water was added. After maintaining the temperature at 80 ° C. for 30 minutes after charging the aqueous hydrogen peroxide solution, 28.1 parts of methacrylic acid was dropped into the reaction vessel over 3 hours, and at the same time, L-ascorbic acid was added to 9.13 parts of ion-exchanged water. An aqueous solution in which 611 parts were dissolved was added dropwise over 3.5 hours. Thereafter, the temperature was maintained at 80 ° C. continuously for 1 hour to complete the polymerization reaction. The concentration of the polymerization components (weight% concentration of all monomer components with respect to all raw materials) was 20%. Thereafter, the reaction solution was adjusted to pH 7 using an aqueous solution of sodium hydroxide at a temperature lower than the polymerization reaction temperature.
To obtain a comparative cement dispersant (DC4).

The conversion (%) of each raw material monomer, the copolymer composition ratio (%) of the copolymer contained in the obtained dispersant, the amount of the structural unit derived from the unsaturated polyalkylene glycol ether monomer (Mol%), amount of carboxylic acid in terms of unneutralized copolymer (meq / g), weight average molecular weight, content of unsaturated polyalkylene glycol ether-based monomer relative to neutralized copolymer (%) Table 3 shows the content (%) of the polyalkylene glycol relative to the neutralized copolymer.

Comparative Example 5 88.3 parts of ion-exchanged water and an average of 50 moles of ethylene oxide were added to allyl alcohol in a glass reactor equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser. 166.6 parts of the obtained unsaturated polyalkylene glycol ether-based monomer (excluding polyalkylene glycol) and 13.4 parts of maleic acid were charged, and the temperature was raised to 65 ° C. 6 reaction vessels
While maintaining the temperature at 5 ° C., 1.7 parts of a 30% aqueous solution of hydrogen peroxide was added. Next, an aqueous solution in which 0.7 part of L-ascorbic acid was dissolved in 29.3 parts of ion-exchanged water was dropped over 3.5 hours. Thereafter, the temperature was maintained at 65 ° C. for 1 hour to complete the polymerization reaction. The concentration of the polymerization components (weight% concentration of all monomer components with respect to all raw materials) is 60%.
Met. Thereafter, the reaction solution was neutralized to pH 7 using an aqueous sodium hydroxide solution at a temperature equal to or lower than the polymerization reaction temperature to obtain a comparative cement dispersant (DC5).

The conversion (%) of each raw material monomer, the copolymer composition ratio (%) of the copolymer contained in the obtained dispersant, and the amount of the structural unit derived from the unsaturated polyalkylene glycol ether-based monomer (Mol%), amount of carboxylic acid in terms of unneutralized copolymer (meq / g), weight average molecular weight, content of unsaturated polyalkylene glycol ether-based monomer relative to neutralized copolymer (%) Table 3 shows the content (%) of the polyalkylene glycol relative to the neutralized copolymer.

[0142]

[Table 2]

[0143]

[Table 3]

In Tables 2 and 3, the following abbreviations were used. AO body: unsaturated polyalkylene glycol ether monomer AA: acrylic acid MAA: methacrylic acid HEA: 2-hydroxyethyl acrylate MA: maleic acid <Concrete test> The cement dispersant of the present invention obtained as described above. Concrete compositions were prepared using (D1) to (D12) and comparative cement dispersants (DC1) to (DC5), and the time-dependent change in slump flow value, the amount of air, and the kneading time were measured by the following methods. Table 4 shows the results.

(Preparation of Concrete Composition) First, 505.3 kg / m ³ of fine aggregate (land sand produced by the Oigawa Water System) was added.
After kneading for 10 seconds with a forced bread mixer, cement (Normal Portland cement made by Taiheiyo Cement) 6
60 kg / m ³ was added and kneaded for 10 seconds. Then, 165 kg / m ^{3 of} tap water containing a cement dispersant in an amount such that the initial slump flow value becomes 600 ± 50 mm is added to 9
Kneaded for 0 seconds. However, the time required for the composition to be uniform is 60.
If the time is longer than 30 seconds, another 30
Kneading was continued for a second. Thereafter, 941.3 kg / m ³ of coarse aggregate (crushed stone from Ome) was further added and kneaded for 90 seconds.
A concrete composition was obtained. In order to avoid the influence of air bubbles in the concrete composition on the fluidity of the concrete composition, a commercially available oxyalkylene-based defoaming agent was used to adjust the air amount to 1.0 ± 0.3 vol%. It was adjusted. In addition, water / cement ratio (weight ratio) = 0.25, fine aggregate ratio [fine aggregate / (fine aggregate + coarse aggregate)] (volume ratio) =
0.403. Table 4 shows the amount of the cement dispersant used for the cement (the amount of solid content [non-volatile content] in the cement dispersant with respect to the cement) (% by weight) and the amount of the copolymer in the cement dispersant with respect to the cement (% by weight). Show. The solid content [non-volatile content] in the cement dispersant is
Volatile components are removed by heating and drying an appropriate amount of cement dispersant at 130 ° C to measure. When blending with cement, the dispersant is measured and used so that a predetermined amount of solid content [non-volatile content] is contained. did.

(Change over time in slump flow value) JIS
-Measured according to A-1101.

(Air Volume) The air volume was measured according to JIS-A-1128.

(Kneading Time) The time required for kneading from the addition of tap water and the cement dispersant to the addition of the coarse aggregate during the preparation of the concrete composition was taken as the kneading time.

<Measurement of setting time> Ion exchange containing 1500 g of cement (Normal Portland cement made by Taiheiyo Cement) containing the cement dispersants (D1) to (D12) of the present invention or the comparative cement dispersants (DC1) to (DC5) A cement paste is prepared by adding 375 g of water (water / cement ratio (weight ratio) = 0.25) and kneading at a medium speed for 5 minutes using a Hobart mortar mixer (manufactured by Hobart, model number N-50). did. The amount of the cement dispersant used for the cement (the amount of solids [non-volatile content] in the cement dispersant relative to the cement) (% by weight)
The amount obtained was a slump flow value of 600 ± 50 mm in the above concrete test.

The obtained cement paste was immediately put into a 1000 ml glass bottle whose periphery was covered with a heat insulating material, and a thermometer connected to a thermometer was fixed to the center of the cement paste, and the change of the temperature of the cement paste with time was measured. It was measured. The time from the start of kneading to the time when the maximum temperature was reached by the heat generated during the hardening of the cement paste was defined as the hardening time. Table 4 shows the results.

[0151]

[Table 4]

From Table 4, it is clear that in each case where the comparative cement dispersant was used, the amount of use required to obtain a sufficient slump flow value increased, and the curing time was prolonged. In addition, it is apparent that if the kneading time is short, the change with time of the slump flow value is large and the fluidity is significantly reduced, while if the change with time of the slump flow value is relatively small, the kneading time is significantly long. In contrast, when using the cement dispersant of the present invention,
It is evident that the amount used to obtain a sufficient slump flow value is small, the curing time is short, the change with time in the slump flow value is small, and the kneading time is short.

[0153]

According to the present invention, it is possible to provide a cement dispersant which exhibits high dispersibility with a small amount of addition and exhibits excellent dispersibility even in a high water reduction region.

Further, according to the cement composition containing the cement dispersant of the present invention, excellent fluidity is exhibited and curing is quick, so that it is possible to improve obstacles in construction.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C04B 103: 32 C04B 103: 32 (72) Inventor Masaya Yamamoto 14-1, Chidoricho, Kawasaki-ku, Kawasaki-shi, Kawasaki, Kanagawa Prefecture Nippon Shokubai Co., Ltd. (72) Inventor Tohru Uno 14-1, Chidori-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture (72) Inventor Yoshiyuki Onda 14-1, Chidori-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Within Nippon Shokubai Co., Ltd. (72) Inventor Ken Ken Hida 5-8, Nishiobari-cho, Suita-shi, Osaka F-term (reference) 4G012 PA02 PA04 PA07 PB29 PB31 PB33 PB36 PC01 PC03 PC12 PC14 4J027 AC02 AC03 AC07 AJ08 BA02 BA06 CA10 CB02 CB03 CB09 CC02 CD00

Claims (6)

[Claims] 1. A structural unit (I) derived from an unsaturated polyalkylene glycol ether monomer (a1) represented by the following general formula (1) and an unsaturated monocarboxylic acid represented by the following general formula (2) Structural unit (II) derived from system monomer (b)
A cement dispersant comprising, as an essential component, a copolymer comprising: wherein the structural unit (II) contains at least a structure derived from methacrylic acid (salt). Embedded image (In the formula (1), X represents an alkenyl group having 2 or 3 carbon atoms, R ¹ O represents ^one or a mixture of two or more oxyalkylene groups having 2 to 18 carbon atoms, and 90 mol% or more of the alkylene groups are oxyethylene groups, and n is the average number of moles of the oxyalkylene groups added, and represents a number of 30 to 1,000.) (In the formula (2), R ² , R ³ , and R ⁴ each independently represent hydrogen or a methyl group, and M represents hydrogen, a monovalent metal, a divalent metal, an ammonium group, or an organic amine group.) 2. A structural unit (III) derived from an unsaturated polyalkylene glycol ether monomer (a2) represented by the following general formula (3) and an unsaturated monocarboxylic acid represented by the following general formula (2) Structural unit (I) derived from the system monomer (b)
A cement dispersant comprising, as an essential component, a copolymer comprising I), wherein the structural unit (III) accounts for 50 mol% or less of all the structural units of the copolymer, and the structural unit ( II) contains at least a structure derived from methacrylic acid (salt), and the carboxyl group milliequivalent number when all the carboxyl groups of the copolymer are converted into an unneutralized type is 3.30 meq / g of the copolymer. A cement dispersant comprising: Embedded image (In the formula (3), Y represents an alkenyl group having 4 carbon atoms,
R ¹ O represents ^one or a mixture of two or more oxyalkylene groups having 2 to 18 carbon atoms, and 90 mol% or more of all oxyalkylene groups are oxyethylene groups;
Is the average number of moles of the oxyalkylene group added,
Represents the number 1000. ) (In the formula (2), R ² , R ³ , and R ⁴ each independently represent hydrogen or a methyl group, and M represents hydrogen, a monovalent metal, a divalent metal, an ammonium group, or an organic amine group.) 3. The cement dispersant according to claim 1, further comprising 1 to 50% by weight of the copolymer, a polyalkylene glycol. 4. 1 to 100% by weight based on the copolymer
The cement dispersant according to any one of claims 1 to 3, further comprising the unsaturated polyalkylene glycol ether-based monomer (a1) or the unsaturated polyalkylene glycol ether-based monomer (a2). . 5. An unsaturated polyalkylene glycol ether monomer having an alkenyl group having 2 to 4 carbon atoms (a)
A method for producing a cement dispersant, comprising polymerizing a monomer component comprising at least an unsaturated monocarboxylic acid-based monomer (b) and an unsaturated monocarboxylic acid-based monomer (b). Unreacted unsaturated polyalkylene glycol ether-based monomer (a) using isomer (a) as a monomer component
A method for producing a cement dispersant, wherein the polymerization reaction is stopped at a time when the amount of the polymer becomes 1 to 100% by weight based on the produced polymer. 6. A cement composition comprising the cement dispersant according to any one of claims 1 to 4, cement and water as essential components.